1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* SCTP kernel implementation
3 * (C) Copyright IBM Corp. 2001, 2004
4 * Copyright (c) 1999-2000 Cisco, Inc.
5 * Copyright (c) 1999-2001 Motorola, Inc.
6 * Copyright (c) 2001-2002 Intel Corp.
7 *
8 * This file is part of the SCTP kernel implementation
9 *
10 * These functions work with the state functions in sctp_sm_statefuns.c
11 * to implement the state operations. These functions implement the
12 * steps which require modifying existing data structures.
13 *
14 * Please send any bug reports or fixes you make to the
15 * email address(es):
16 * lksctp developers <linux-sctp@vger.kernel.org>
17 *
18 * Written or modified by:
19 * La Monte H.P. Yarroll <piggy@acm.org>
20 * Karl Knutson <karl@athena.chicago.il.us>
21 * C. Robin <chris@hundredacre.ac.uk>
22 * Jon Grimm <jgrimm@us.ibm.com>
23 * Xingang Guo <xingang.guo@intel.com>
24 * Dajiang Zhang <dajiang.zhang@nokia.com>
25 * Sridhar Samudrala <sri@us.ibm.com>
26 * Daisy Chang <daisyc@us.ibm.com>
27 * Ardelle Fan <ardelle.fan@intel.com>
28 * Kevin Gao <kevin.gao@intel.com>
29 */
30
31 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
32
33 #include <crypto/hash.h>
34 #include <linux/types.h>
35 #include <linux/kernel.h>
36 #include <linux/ip.h>
37 #include <linux/ipv6.h>
38 #include <linux/net.h>
39 #include <linux/inet.h>
40 #include <linux/scatterlist.h>
41 #include <linux/slab.h>
42 #include <net/sock.h>
43
44 #include <linux/skbuff.h>
45 #include <linux/random.h> /* for get_random_bytes */
46 #include <net/sctp/sctp.h>
47 #include <net/sctp/sm.h>
48
49 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc,
50 __u8 type, __u8 flags, int paylen,
51 gfp_t gfp);
52 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc,
53 __u8 flags, int paylen, gfp_t gfp);
54 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc,
55 __u8 type, __u8 flags, int paylen,
56 gfp_t gfp);
57 static struct sctp_cookie_param *sctp_pack_cookie(
58 const struct sctp_endpoint *ep,
59 const struct sctp_association *asoc,
60 const struct sctp_chunk *init_chunk,
61 int *cookie_len,
62 const __u8 *raw_addrs, int addrs_len);
63 static int sctp_process_param(struct sctp_association *asoc,
64 union sctp_params param,
65 const union sctp_addr *peer_addr,
66 gfp_t gfp);
67 static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
68 const void *data);
69
70 /* Control chunk destructor */
71 static void sctp_control_release_owner(struct sk_buff *skb)
72 {
73 struct sctp_chunk *chunk = skb_shinfo(skb)->destructor_arg;
74
75 if (chunk->shkey) {
76 struct sctp_shared_key *shkey = chunk->shkey;
77 struct sctp_association *asoc = chunk->asoc;
78
79 /* refcnt == 2 and !list_empty mean after this release, it's
80 * not being used anywhere, and it's time to notify userland
81 * that this shkey can be freed if it's been deactivated.
82 */
83 if (shkey->deactivated && !list_empty(&shkey->key_list) &&
84 refcount_read(&shkey->refcnt) == 2) {
85 struct sctp_ulpevent *ev;
86
87 ev = sctp_ulpevent_make_authkey(asoc, shkey->key_id,
88 SCTP_AUTH_FREE_KEY,
89 GFP_KERNEL);
90 if (ev)
91 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
92 }
93 sctp_auth_shkey_release(chunk->shkey);
94 }
95 }
96
97 static void sctp_control_set_owner_w(struct sctp_chunk *chunk)
98 {
99 struct sctp_association *asoc = chunk->asoc;
100 struct sk_buff *skb = chunk->skb;
101
102 /* TODO: properly account for control chunks.
103 * To do it right we'll need:
104 * 1) endpoint if association isn't known.
105 * 2) proper memory accounting.
106 *
107 * For now don't do anything for now.
108 */
109 if (chunk->auth) {
110 chunk->shkey = asoc->shkey;
111 sctp_auth_shkey_hold(chunk->shkey);
112 }
113 skb->sk = asoc ? asoc->base.sk : NULL;
114 skb_shinfo(skb)->destructor_arg = chunk;
115 skb->destructor = sctp_control_release_owner;
116 }
117
118 /* What was the inbound interface for this chunk? */
119 int sctp_chunk_iif(const struct sctp_chunk *chunk)
120 {
121 struct sk_buff *skb = chunk->skb;
122
123 return SCTP_INPUT_CB(skb)->af->skb_iif(skb);
124 }
125
126 /* RFC 2960 3.3.2 Initiation (INIT) (1)
127 *
128 * Note 2: The ECN capable field is reserved for future use of
129 * Explicit Congestion Notification.
130 */
131 static const struct sctp_paramhdr ecap_param = {
132 SCTP_PARAM_ECN_CAPABLE,
133 cpu_to_be16(sizeof(struct sctp_paramhdr)),
134 };
135 static const struct sctp_paramhdr prsctp_param = {
136 SCTP_PARAM_FWD_TSN_SUPPORT,
137 cpu_to_be16(sizeof(struct sctp_paramhdr)),
138 };
139
140 /* A helper to initialize an op error inside a provided chunk, as most
141 * cause codes will be embedded inside an abort chunk.
142 */
143 int sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code,
144 size_t paylen)
145 {
146 struct sctp_errhdr err;
147 __u16 len;
148
149 /* Cause code constants are now defined in network order. */
150 err.cause = cause_code;
151 len = sizeof(err) + paylen;
152 err.length = htons(len);
153
154 if (skb_tailroom(chunk->skb) < len)
155 return -ENOSPC;
156
157 chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(err), &err);
158
159 return 0;
160 }
161
162 /* 3.3.2 Initiation (INIT) (1)
163 *
164 * This chunk is used to initiate a SCTP association between two
165 * endpoints. The format of the INIT chunk is shown below:
166 *
167 * 0 1 2 3
168 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
169 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
170 * | Type = 1 | Chunk Flags | Chunk Length |
171 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
172 * | Initiate Tag |
173 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
174 * | Advertised Receiver Window Credit (a_rwnd) |
175 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
176 * | Number of Outbound Streams | Number of Inbound Streams |
177 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
178 * | Initial TSN |
179 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
180 * \ \
181 * / Optional/Variable-Length Parameters /
182 * \ \
183 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
184 *
185 *
186 * The INIT chunk contains the following parameters. Unless otherwise
187 * noted, each parameter MUST only be included once in the INIT chunk.
188 *
189 * Fixed Parameters Status
190 * ----------------------------------------------
191 * Initiate Tag Mandatory
192 * Advertised Receiver Window Credit Mandatory
193 * Number of Outbound Streams Mandatory
194 * Number of Inbound Streams Mandatory
195 * Initial TSN Mandatory
196 *
197 * Variable Parameters Status Type Value
198 * -------------------------------------------------------------
199 * IPv4 Address (Note 1) Optional 5
200 * IPv6 Address (Note 1) Optional 6
201 * Cookie Preservative Optional 9
202 * Reserved for ECN Capable (Note 2) Optional 32768 (0x8000)
203 * Host Name Address (Note 3) Optional 11
204 * Supported Address Types (Note 4) Optional 12
205 */
206 struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc,
207 const struct sctp_bind_addr *bp,
208 gfp_t gfp, int vparam_len)
209 {
210 struct sctp_supported_ext_param ext_param;
211 struct sctp_adaptation_ind_param aiparam;
212 struct sctp_paramhdr *auth_chunks = NULL;
213 struct sctp_paramhdr *auth_hmacs = NULL;
214 struct sctp_supported_addrs_param sat;
215 struct sctp_endpoint *ep = asoc->ep;
216 struct sctp_chunk *retval = NULL;
217 int num_types, addrs_len = 0;
218 struct sctp_inithdr init;
219 union sctp_params addrs;
220 struct sctp_sock *sp;
221 __u8 extensions[5];
222 size_t chunksize;
223 __be16 types[2];
224 int num_ext = 0;
225
226 /* RFC 2960 3.3.2 Initiation (INIT) (1)
227 *
228 * Note 1: The INIT chunks can contain multiple addresses that
229 * can be IPv4 and/or IPv6 in any combination.
230 */
231
232 /* Convert the provided bind address list to raw format. */
233 addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp);
234
235 init.init_tag = htonl(asoc->c.my_vtag);
236 init.a_rwnd = htonl(asoc->rwnd);
237 init.num_outbound_streams = htons(asoc->c.sinit_num_ostreams);
238 init.num_inbound_streams = htons(asoc->c.sinit_max_instreams);
239 init.initial_tsn = htonl(asoc->c.initial_tsn);
240
241 /* How many address types are needed? */
242 sp = sctp_sk(asoc->base.sk);
243 num_types = sp->pf->supported_addrs(sp, types);
244
245 chunksize = sizeof(init) + addrs_len;
246 chunksize += SCTP_PAD4(SCTP_SAT_LEN(num_types));
247
248 if (asoc->ep->ecn_enable)
249 chunksize += sizeof(ecap_param);
250
251 if (asoc->ep->prsctp_enable)
252 chunksize += sizeof(prsctp_param);
253
254 /* ADDIP: Section 4.2.7:
255 * An implementation supporting this extension [ADDIP] MUST list
256 * the ASCONF,the ASCONF-ACK, and the AUTH chunks in its INIT and
257 * INIT-ACK parameters.
258 */
259 if (asoc->ep->asconf_enable) {
260 extensions[num_ext] = SCTP_CID_ASCONF;
261 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
262 num_ext += 2;
263 }
264
265 if (asoc->ep->reconf_enable) {
266 extensions[num_ext] = SCTP_CID_RECONF;
267 num_ext += 1;
268 }
269
270 if (sp->adaptation_ind)
271 chunksize += sizeof(aiparam);
272
273 if (asoc->ep->intl_enable) {
274 extensions[num_ext] = SCTP_CID_I_DATA;
275 num_ext += 1;
276 }
277
278 chunksize += vparam_len;
279
280 /* Account for AUTH related parameters */
281 if (ep->auth_enable) {
282 /* Add random parameter length*/
283 chunksize += sizeof(asoc->c.auth_random);
284
285 /* Add HMACS parameter length if any were defined */
286 auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs;
287 if (auth_hmacs->length)
288 chunksize += SCTP_PAD4(ntohs(auth_hmacs->length));
289 else
290 auth_hmacs = NULL;
291
292 /* Add CHUNKS parameter length */
293 auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks;
294 if (auth_chunks->length)
295 chunksize += SCTP_PAD4(ntohs(auth_chunks->length));
296 else
297 auth_chunks = NULL;
298
299 extensions[num_ext] = SCTP_CID_AUTH;
300 num_ext += 1;
301 }
302
303 /* If we have any extensions to report, account for that */
304 if (num_ext)
305 chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext);
306
307 /* RFC 2960 3.3.2 Initiation (INIT) (1)
308 *
309 * Note 3: An INIT chunk MUST NOT contain more than one Host
310 * Name address parameter. Moreover, the sender of the INIT
311 * MUST NOT combine any other address types with the Host Name
312 * address in the INIT. The receiver of INIT MUST ignore any
313 * other address types if the Host Name address parameter is
314 * present in the received INIT chunk.
315 *
316 * PLEASE DO NOT FIXME [This version does not support Host Name.]
317 */
318
319 retval = sctp_make_control(asoc, SCTP_CID_INIT, 0, chunksize, gfp);
320 if (!retval)
321 goto nodata;
322
323 retval->subh.init_hdr =
324 sctp_addto_chunk(retval, sizeof(init), &init);
325 retval->param_hdr.v =
326 sctp_addto_chunk(retval, addrs_len, addrs.v);
327
328 /* RFC 2960 3.3.2 Initiation (INIT) (1)
329 *
330 * Note 4: This parameter, when present, specifies all the
331 * address types the sending endpoint can support. The absence
332 * of this parameter indicates that the sending endpoint can
333 * support any address type.
334 */
335 sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES;
336 sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types));
337 sctp_addto_chunk(retval, sizeof(sat), &sat);
338 sctp_addto_chunk(retval, num_types * sizeof(__u16), &types);
339
340 if (asoc->ep->ecn_enable)
341 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
342
343 /* Add the supported extensions parameter. Be nice and add this
344 * fist before addiding the parameters for the extensions themselves
345 */
346 if (num_ext) {
347 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
348 ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext);
349 sctp_addto_chunk(retval, sizeof(ext_param), &ext_param);
350 sctp_addto_param(retval, num_ext, extensions);
351 }
352
353 if (asoc->ep->prsctp_enable)
354 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
355
356 if (sp->adaptation_ind) {
357 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
358 aiparam.param_hdr.length = htons(sizeof(aiparam));
359 aiparam.adaptation_ind = htonl(sp->adaptation_ind);
360 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
361 }
362
363 /* Add SCTP-AUTH chunks to the parameter list */
364 if (ep->auth_enable) {
365 sctp_addto_chunk(retval, sizeof(asoc->c.auth_random),
366 asoc->c.auth_random);
367 if (auth_hmacs)
368 sctp_addto_chunk(retval, ntohs(auth_hmacs->length),
369 auth_hmacs);
370 if (auth_chunks)
371 sctp_addto_chunk(retval, ntohs(auth_chunks->length),
372 auth_chunks);
373 }
374 nodata:
375 kfree(addrs.v);
376 return retval;
377 }
378
379 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc,
380 const struct sctp_chunk *chunk,
381 gfp_t gfp, int unkparam_len)
382 {
383 struct sctp_supported_ext_param ext_param;
384 struct sctp_adaptation_ind_param aiparam;
385 struct sctp_paramhdr *auth_chunks = NULL;
386 struct sctp_paramhdr *auth_random = NULL;
387 struct sctp_paramhdr *auth_hmacs = NULL;
388 struct sctp_chunk *retval = NULL;
389 struct sctp_cookie_param *cookie;
390 struct sctp_inithdr initack;
391 union sctp_params addrs;
392 struct sctp_sock *sp;
393 __u8 extensions[5];
394 size_t chunksize;
395 int num_ext = 0;
396 int cookie_len;
397 int addrs_len;
398
399 /* Note: there may be no addresses to embed. */
400 addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp);
401
402 initack.init_tag = htonl(asoc->c.my_vtag);
403 initack.a_rwnd = htonl(asoc->rwnd);
404 initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams);
405 initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams);
406 initack.initial_tsn = htonl(asoc->c.initial_tsn);
407
408 /* FIXME: We really ought to build the cookie right
409 * into the packet instead of allocating more fresh memory.
410 */
411 cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len,
412 addrs.v, addrs_len);
413 if (!cookie)
414 goto nomem_cookie;
415
416 /* Calculate the total size of allocation, include the reserved
417 * space for reporting unknown parameters if it is specified.
418 */
419 sp = sctp_sk(asoc->base.sk);
420 chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len;
421
422 /* Tell peer that we'll do ECN only if peer advertised such cap. */
423 if (asoc->peer.ecn_capable)
424 chunksize += sizeof(ecap_param);
425
426 if (asoc->peer.prsctp_capable)
427 chunksize += sizeof(prsctp_param);
428
429 if (asoc->peer.asconf_capable) {
430 extensions[num_ext] = SCTP_CID_ASCONF;
431 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
432 num_ext += 2;
433 }
434
435 if (asoc->peer.reconf_capable) {
436 extensions[num_ext] = SCTP_CID_RECONF;
437 num_ext += 1;
438 }
439
440 if (sp->adaptation_ind)
441 chunksize += sizeof(aiparam);
442
443 if (asoc->peer.intl_capable) {
444 extensions[num_ext] = SCTP_CID_I_DATA;
445 num_ext += 1;
446 }
447
448 if (asoc->peer.auth_capable) {
449 auth_random = (struct sctp_paramhdr *)asoc->c.auth_random;
450 chunksize += ntohs(auth_random->length);
451
452 auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs;
453 if (auth_hmacs->length)
454 chunksize += SCTP_PAD4(ntohs(auth_hmacs->length));
455 else
456 auth_hmacs = NULL;
457
458 auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks;
459 if (auth_chunks->length)
460 chunksize += SCTP_PAD4(ntohs(auth_chunks->length));
461 else
462 auth_chunks = NULL;
463
464 extensions[num_ext] = SCTP_CID_AUTH;
465 num_ext += 1;
466 }
467
468 if (num_ext)
469 chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext);
470
471 /* Now allocate and fill out the chunk. */
472 retval = sctp_make_control(asoc, SCTP_CID_INIT_ACK, 0, chunksize, gfp);
473 if (!retval)
474 goto nomem_chunk;
475
476 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
477 *
478 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
479 * HEARTBEAT ACK, * etc.) to the same destination transport
480 * address from which it received the DATA or control chunk
481 * to which it is replying.
482 *
483 * [INIT ACK back to where the INIT came from.]
484 */
485 if (chunk->transport)
486 retval->transport =
487 sctp_assoc_lookup_paddr(asoc,
488 &chunk->transport->ipaddr);
489
490 retval->subh.init_hdr =
491 sctp_addto_chunk(retval, sizeof(initack), &initack);
492 retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v);
493 sctp_addto_chunk(retval, cookie_len, cookie);
494 if (asoc->peer.ecn_capable)
495 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
496 if (num_ext) {
497 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
498 ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext);
499 sctp_addto_chunk(retval, sizeof(ext_param), &ext_param);
500 sctp_addto_param(retval, num_ext, extensions);
501 }
502 if (asoc->peer.prsctp_capable)
503 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
504
505 if (sp->adaptation_ind) {
506 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
507 aiparam.param_hdr.length = htons(sizeof(aiparam));
508 aiparam.adaptation_ind = htonl(sp->adaptation_ind);
509 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
510 }
511
512 if (asoc->peer.auth_capable) {
513 sctp_addto_chunk(retval, ntohs(auth_random->length),
514 auth_random);
515 if (auth_hmacs)
516 sctp_addto_chunk(retval, ntohs(auth_hmacs->length),
517 auth_hmacs);
518 if (auth_chunks)
519 sctp_addto_chunk(retval, ntohs(auth_chunks->length),
520 auth_chunks);
521 }
522
523 /* We need to remove the const qualifier at this point. */
524 retval->asoc = (struct sctp_association *) asoc;
525
526 nomem_chunk:
527 kfree(cookie);
528 nomem_cookie:
529 kfree(addrs.v);
530 return retval;
531 }
532
533 /* 3.3.11 Cookie Echo (COOKIE ECHO) (10):
534 *
535 * This chunk is used only during the initialization of an association.
536 * It is sent by the initiator of an association to its peer to complete
537 * the initialization process. This chunk MUST precede any DATA chunk
538 * sent within the association, but MAY be bundled with one or more DATA
539 * chunks in the same packet.
540 *
541 * 0 1 2 3
542 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
543 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
544 * | Type = 10 |Chunk Flags | Length |
545 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
546 * / Cookie /
547 * \ \
548 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
549 *
550 * Chunk Flags: 8 bit
551 *
552 * Set to zero on transmit and ignored on receipt.
553 *
554 * Length: 16 bits (unsigned integer)
555 *
556 * Set to the size of the chunk in bytes, including the 4 bytes of
557 * the chunk header and the size of the Cookie.
558 *
559 * Cookie: variable size
560 *
561 * This field must contain the exact cookie received in the
562 * State Cookie parameter from the previous INIT ACK.
563 *
564 * An implementation SHOULD make the cookie as small as possible
565 * to insure interoperability.
566 */
567 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc,
568 const struct sctp_chunk *chunk)
569 {
570 struct sctp_chunk *retval;
571 int cookie_len;
572 void *cookie;
573
574 cookie = asoc->peer.cookie;
575 cookie_len = asoc->peer.cookie_len;
576
577 /* Build a cookie echo chunk. */
578 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ECHO, 0,
579 cookie_len, GFP_ATOMIC);
580 if (!retval)
581 goto nodata;
582 retval->subh.cookie_hdr =
583 sctp_addto_chunk(retval, cookie_len, cookie);
584
585 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
586 *
587 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
588 * HEARTBEAT ACK, * etc.) to the same destination transport
589 * address from which it * received the DATA or control chunk
590 * to which it is replying.
591 *
592 * [COOKIE ECHO back to where the INIT ACK came from.]
593 */
594 if (chunk)
595 retval->transport = chunk->transport;
596
597 nodata:
598 return retval;
599 }
600
601 /* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11):
602 *
603 * This chunk is used only during the initialization of an
604 * association. It is used to acknowledge the receipt of a COOKIE
605 * ECHO chunk. This chunk MUST precede any DATA or SACK chunk sent
606 * within the association, but MAY be bundled with one or more DATA
607 * chunks or SACK chunk in the same SCTP packet.
608 *
609 * 0 1 2 3
610 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
611 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
612 * | Type = 11 |Chunk Flags | Length = 4 |
613 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
614 *
615 * Chunk Flags: 8 bits
616 *
617 * Set to zero on transmit and ignored on receipt.
618 */
619 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc,
620 const struct sctp_chunk *chunk)
621 {
622 struct sctp_chunk *retval;
623
624 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ACK, 0, 0, GFP_ATOMIC);
625
626 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
627 *
628 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
629 * HEARTBEAT ACK, * etc.) to the same destination transport
630 * address from which it * received the DATA or control chunk
631 * to which it is replying.
632 *
633 * [COOKIE ACK back to where the COOKIE ECHO came from.]
634 */
635 if (retval && chunk && chunk->transport)
636 retval->transport =
637 sctp_assoc_lookup_paddr(asoc,
638 &chunk->transport->ipaddr);
639
640 return retval;
641 }
642
643 /*
644 * Appendix A: Explicit Congestion Notification:
645 * CWR:
646 *
647 * RFC 2481 details a specific bit for a sender to send in the header of
648 * its next outbound TCP segment to indicate to its peer that it has
649 * reduced its congestion window. This is termed the CWR bit. For
650 * SCTP the same indication is made by including the CWR chunk.
651 * This chunk contains one data element, i.e. the TSN number that
652 * was sent in the ECNE chunk. This element represents the lowest
653 * TSN number in the datagram that was originally marked with the
654 * CE bit.
655 *
656 * 0 1 2 3
657 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
658 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
659 * | Chunk Type=13 | Flags=00000000| Chunk Length = 8 |
660 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
661 * | Lowest TSN Number |
662 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
663 *
664 * Note: The CWR is considered a Control chunk.
665 */
666 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc,
667 const __u32 lowest_tsn,
668 const struct sctp_chunk *chunk)
669 {
670 struct sctp_chunk *retval;
671 struct sctp_cwrhdr cwr;
672
673 cwr.lowest_tsn = htonl(lowest_tsn);
674 retval = sctp_make_control(asoc, SCTP_CID_ECN_CWR, 0,
675 sizeof(cwr), GFP_ATOMIC);
676
677 if (!retval)
678 goto nodata;
679
680 retval->subh.ecn_cwr_hdr =
681 sctp_addto_chunk(retval, sizeof(cwr), &cwr);
682
683 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
684 *
685 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
686 * HEARTBEAT ACK, * etc.) to the same destination transport
687 * address from which it * received the DATA or control chunk
688 * to which it is replying.
689 *
690 * [Report a reduced congestion window back to where the ECNE
691 * came from.]
692 */
693 if (chunk)
694 retval->transport = chunk->transport;
695
696 nodata:
697 return retval;
698 }
699
700 /* Make an ECNE chunk. This is a congestion experienced report. */
701 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc,
702 const __u32 lowest_tsn)
703 {
704 struct sctp_chunk *retval;
705 struct sctp_ecnehdr ecne;
706
707 ecne.lowest_tsn = htonl(lowest_tsn);
708 retval = sctp_make_control(asoc, SCTP_CID_ECN_ECNE, 0,
709 sizeof(ecne), GFP_ATOMIC);
710 if (!retval)
711 goto nodata;
712 retval->subh.ecne_hdr =
713 sctp_addto_chunk(retval, sizeof(ecne), &ecne);
714
715 nodata:
716 return retval;
717 }
718
719 /* Make a DATA chunk for the given association from the provided
720 * parameters. However, do not populate the data payload.
721 */
722 struct sctp_chunk *sctp_make_datafrag_empty(const struct sctp_association *asoc,
723 const struct sctp_sndrcvinfo *sinfo,
724 int len, __u8 flags, gfp_t gfp)
725 {
726 struct sctp_chunk *retval;
727 struct sctp_datahdr dp;
728
729 /* We assign the TSN as LATE as possible, not here when
730 * creating the chunk.
731 */
732 memset(&dp, 0, sizeof(dp));
733 dp.ppid = sinfo->sinfo_ppid;
734 dp.stream = htons(sinfo->sinfo_stream);
735
736 /* Set the flags for an unordered send. */
737 if (sinfo->sinfo_flags & SCTP_UNORDERED)
738 flags |= SCTP_DATA_UNORDERED;
739
740 retval = sctp_make_data(asoc, flags, sizeof(dp) + len, gfp);
741 if (!retval)
742 return NULL;
743
744 retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp);
745 memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo));
746
747 return retval;
748 }
749
750 /* Create a selective ackowledgement (SACK) for the given
751 * association. This reports on which TSN's we've seen to date,
752 * including duplicates and gaps.
753 */
754 struct sctp_chunk *sctp_make_sack(struct sctp_association *asoc)
755 {
756 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
757 struct sctp_gap_ack_block gabs[SCTP_MAX_GABS];
758 __u16 num_gabs, num_dup_tsns;
759 struct sctp_transport *trans;
760 struct sctp_chunk *retval;
761 struct sctp_sackhdr sack;
762 __u32 ctsn;
763 int len;
764
765 memset(gabs, 0, sizeof(gabs));
766 ctsn = sctp_tsnmap_get_ctsn(map);
767
768 pr_debug("%s: sackCTSNAck sent:0x%x\n", __func__, ctsn);
769
770 /* How much room is needed in the chunk? */
771 num_gabs = sctp_tsnmap_num_gabs(map, gabs);
772 num_dup_tsns = sctp_tsnmap_num_dups(map);
773
774 /* Initialize the SACK header. */
775 sack.cum_tsn_ack = htonl(ctsn);
776 sack.a_rwnd = htonl(asoc->a_rwnd);
777 sack.num_gap_ack_blocks = htons(num_gabs);
778 sack.num_dup_tsns = htons(num_dup_tsns);
779
780 len = sizeof(sack)
781 + sizeof(struct sctp_gap_ack_block) * num_gabs
782 + sizeof(__u32) * num_dup_tsns;
783
784 /* Create the chunk. */
785 retval = sctp_make_control(asoc, SCTP_CID_SACK, 0, len, GFP_ATOMIC);
786 if (!retval)
787 goto nodata;
788
789 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
790 *
791 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
792 * HEARTBEAT ACK, etc.) to the same destination transport
793 * address from which it received the DATA or control chunk to
794 * which it is replying. This rule should also be followed if
795 * the endpoint is bundling DATA chunks together with the
796 * reply chunk.
797 *
798 * However, when acknowledging multiple DATA chunks received
799 * in packets from different source addresses in a single
800 * SACK, the SACK chunk may be transmitted to one of the
801 * destination transport addresses from which the DATA or
802 * control chunks being acknowledged were received.
803 *
804 * [BUG: We do not implement the following paragraph.
805 * Perhaps we should remember the last transport we used for a
806 * SACK and avoid that (if possible) if we have seen any
807 * duplicates. --piggy]
808 *
809 * When a receiver of a duplicate DATA chunk sends a SACK to a
810 * multi- homed endpoint it MAY be beneficial to vary the
811 * destination address and not use the source address of the
812 * DATA chunk. The reason being that receiving a duplicate
813 * from a multi-homed endpoint might indicate that the return
814 * path (as specified in the source address of the DATA chunk)
815 * for the SACK is broken.
816 *
817 * [Send to the address from which we last received a DATA chunk.]
818 */
819 retval->transport = asoc->peer.last_data_from;
820
821 retval->subh.sack_hdr =
822 sctp_addto_chunk(retval, sizeof(sack), &sack);
823
824 /* Add the gap ack block information. */
825 if (num_gabs)
826 sctp_addto_chunk(retval, sizeof(__u32) * num_gabs,
827 gabs);
828
829 /* Add the duplicate TSN information. */
830 if (num_dup_tsns) {
831 asoc->stats.idupchunks += num_dup_tsns;
832 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns,
833 sctp_tsnmap_get_dups(map));
834 }
835 /* Once we have a sack generated, check to see what our sack
836 * generation is, if its 0, reset the transports to 0, and reset
837 * the association generation to 1
838 *
839 * The idea is that zero is never used as a valid generation for the
840 * association so no transport will match after a wrap event like this,
841 * Until the next sack
842 */
843 if (++asoc->peer.sack_generation == 0) {
844 list_for_each_entry(trans, &asoc->peer.transport_addr_list,
845 transports)
846 trans->sack_generation = 0;
847 asoc->peer.sack_generation = 1;
848 }
849 nodata:
850 return retval;
851 }
852
853 /* Make a SHUTDOWN chunk. */
854 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc,
855 const struct sctp_chunk *chunk)
856 {
857 struct sctp_shutdownhdr shut;
858 struct sctp_chunk *retval;
859 __u32 ctsn;
860
861 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
862 shut.cum_tsn_ack = htonl(ctsn);
863
864 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN, 0,
865 sizeof(shut), GFP_ATOMIC);
866 if (!retval)
867 goto nodata;
868
869 retval->subh.shutdown_hdr =
870 sctp_addto_chunk(retval, sizeof(shut), &shut);
871
872 if (chunk)
873 retval->transport = chunk->transport;
874 nodata:
875 return retval;
876 }
877
878 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc,
879 const struct sctp_chunk *chunk)
880 {
881 struct sctp_chunk *retval;
882
883 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0,
884 GFP_ATOMIC);
885
886 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
887 *
888 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
889 * HEARTBEAT ACK, * etc.) to the same destination transport
890 * address from which it * received the DATA or control chunk
891 * to which it is replying.
892 *
893 * [ACK back to where the SHUTDOWN came from.]
894 */
895 if (retval && chunk)
896 retval->transport = chunk->transport;
897
898 return retval;
899 }
900
901 struct sctp_chunk *sctp_make_shutdown_complete(
902 const struct sctp_association *asoc,
903 const struct sctp_chunk *chunk)
904 {
905 struct sctp_chunk *retval;
906 __u8 flags = 0;
907
908 /* Set the T-bit if we have no association (vtag will be
909 * reflected)
910 */
911 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T;
912
913 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags,
914 0, GFP_ATOMIC);
915
916 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
917 *
918 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
919 * HEARTBEAT ACK, * etc.) to the same destination transport
920 * address from which it * received the DATA or control chunk
921 * to which it is replying.
922 *
923 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK
924 * came from.]
925 */
926 if (retval && chunk)
927 retval->transport = chunk->transport;
928
929 return retval;
930 }
931
932 /* Create an ABORT. Note that we set the T bit if we have no
933 * association, except when responding to an INIT (sctpimpguide 2.41).
934 */
935 struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc,
936 const struct sctp_chunk *chunk,
937 const size_t hint)
938 {
939 struct sctp_chunk *retval;
940 __u8 flags = 0;
941
942 /* Set the T-bit if we have no association and 'chunk' is not
943 * an INIT (vtag will be reflected).
944 */
945 if (!asoc) {
946 if (chunk && chunk->chunk_hdr &&
947 chunk->chunk_hdr->type == SCTP_CID_INIT)
948 flags = 0;
949 else
950 flags = SCTP_CHUNK_FLAG_T;
951 }
952
953 retval = sctp_make_control(asoc, SCTP_CID_ABORT, flags, hint,
954 GFP_ATOMIC);
955
956 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
957 *
958 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
959 * HEARTBEAT ACK, * etc.) to the same destination transport
960 * address from which it * received the DATA or control chunk
961 * to which it is replying.
962 *
963 * [ABORT back to where the offender came from.]
964 */
965 if (retval && chunk)
966 retval->transport = chunk->transport;
967
968 return retval;
969 }
970
971 /* Helper to create ABORT with a NO_USER_DATA error. */
972 struct sctp_chunk *sctp_make_abort_no_data(
973 const struct sctp_association *asoc,
974 const struct sctp_chunk *chunk,
975 __u32 tsn)
976 {
977 struct sctp_chunk *retval;
978 __be32 payload;
979
980 retval = sctp_make_abort(asoc, chunk,
981 sizeof(struct sctp_errhdr) + sizeof(tsn));
982
983 if (!retval)
984 goto no_mem;
985
986 /* Put the tsn back into network byte order. */
987 payload = htonl(tsn);
988 sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload));
989 sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload);
990
991 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
992 *
993 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
994 * HEARTBEAT ACK, * etc.) to the same destination transport
995 * address from which it * received the DATA or control chunk
996 * to which it is replying.
997 *
998 * [ABORT back to where the offender came from.]
999 */
1000 if (chunk)
1001 retval->transport = chunk->transport;
1002
1003 no_mem:
1004 return retval;
1005 }
1006
1007 /* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */
1008 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc,
1009 struct msghdr *msg,
1010 size_t paylen)
1011 {
1012 struct sctp_chunk *retval;
1013 void *payload = NULL;
1014 int err;
1015
1016 retval = sctp_make_abort(asoc, NULL,
1017 sizeof(struct sctp_errhdr) + paylen);
1018 if (!retval)
1019 goto err_chunk;
1020
1021 if (paylen) {
1022 /* Put the msg_iov together into payload. */
1023 payload = kmalloc(paylen, GFP_KERNEL);
1024 if (!payload)
1025 goto err_payload;
1026
1027 err = memcpy_from_msg(payload, msg, paylen);
1028 if (err < 0)
1029 goto err_copy;
1030 }
1031
1032 sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen);
1033 sctp_addto_chunk(retval, paylen, payload);
1034
1035 if (paylen)
1036 kfree(payload);
1037
1038 return retval;
1039
1040 err_copy:
1041 kfree(payload);
1042 err_payload:
1043 sctp_chunk_free(retval);
1044 retval = NULL;
1045 err_chunk:
1046 return retval;
1047 }
1048
1049 /* Append bytes to the end of a parameter. Will panic if chunk is not big
1050 * enough.
1051 */
1052 static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
1053 const void *data)
1054 {
1055 int chunklen = ntohs(chunk->chunk_hdr->length);
1056 void *target;
1057
1058 target = skb_put(chunk->skb, len);
1059
1060 if (data)
1061 memcpy(target, data, len);
1062 else
1063 memset(target, 0, len);
1064
1065 /* Adjust the chunk length field. */
1066 chunk->chunk_hdr->length = htons(chunklen + len);
1067 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1068
1069 return target;
1070 }
1071
1072 /* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */
1073 struct sctp_chunk *sctp_make_abort_violation(
1074 const struct sctp_association *asoc,
1075 const struct sctp_chunk *chunk,
1076 const __u8 *payload,
1077 const size_t paylen)
1078 {
1079 struct sctp_chunk *retval;
1080 struct sctp_paramhdr phdr;
1081
1082 retval = sctp_make_abort(asoc, chunk, sizeof(struct sctp_errhdr) +
1083 paylen + sizeof(phdr));
1084 if (!retval)
1085 goto end;
1086
1087 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen +
1088 sizeof(phdr));
1089
1090 phdr.type = htons(chunk->chunk_hdr->type);
1091 phdr.length = chunk->chunk_hdr->length;
1092 sctp_addto_chunk(retval, paylen, payload);
1093 sctp_addto_param(retval, sizeof(phdr), &phdr);
1094
1095 end:
1096 return retval;
1097 }
1098
1099 struct sctp_chunk *sctp_make_violation_paramlen(
1100 const struct sctp_association *asoc,
1101 const struct sctp_chunk *chunk,
1102 struct sctp_paramhdr *param)
1103 {
1104 static const char error[] = "The following parameter had invalid length:";
1105 size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr) +
1106 sizeof(*param);
1107 struct sctp_chunk *retval;
1108
1109 retval = sctp_make_abort(asoc, chunk, payload_len);
1110 if (!retval)
1111 goto nodata;
1112
1113 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION,
1114 sizeof(error) + sizeof(*param));
1115 sctp_addto_chunk(retval, sizeof(error), error);
1116 sctp_addto_param(retval, sizeof(*param), param);
1117
1118 nodata:
1119 return retval;
1120 }
1121
1122 struct sctp_chunk *sctp_make_violation_max_retrans(
1123 const struct sctp_association *asoc,
1124 const struct sctp_chunk *chunk)
1125 {
1126 static const char error[] = "Association exceeded its max_retrans count";
1127 size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr);
1128 struct sctp_chunk *retval;
1129
1130 retval = sctp_make_abort(asoc, chunk, payload_len);
1131 if (!retval)
1132 goto nodata;
1133
1134 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error));
1135 sctp_addto_chunk(retval, sizeof(error), error);
1136
1137 nodata:
1138 return retval;
1139 }
1140
1141 struct sctp_chunk *sctp_make_new_encap_port(const struct sctp_association *asoc,
1142 const struct sctp_chunk *chunk)
1143 {
1144 struct sctp_new_encap_port_hdr nep;
1145 struct sctp_chunk *retval;
1146
1147 retval = sctp_make_abort(asoc, chunk,
1148 sizeof(struct sctp_errhdr) + sizeof(nep));
1149 if (!retval)
1150 goto nodata;
1151
1152 sctp_init_cause(retval, SCTP_ERROR_NEW_ENCAP_PORT, sizeof(nep));
1153 nep.cur_port = SCTP_INPUT_CB(chunk->skb)->encap_port;
1154 nep.new_port = chunk->transport->encap_port;
1155 sctp_addto_chunk(retval, sizeof(nep), &nep);
1156
1157 nodata:
1158 return retval;
1159 }
1160
1161 /* Make a HEARTBEAT chunk. */
1162 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc,
1163 const struct sctp_transport *transport,
1164 __u32 probe_size)
1165 {
1166 struct sctp_sender_hb_info hbinfo = {};
1167 struct sctp_chunk *retval;
1168
1169 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT, 0,
1170 sizeof(hbinfo), GFP_ATOMIC);
1171
1172 if (!retval)
1173 goto nodata;
1174
1175 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO;
1176 hbinfo.param_hdr.length = htons(sizeof(hbinfo));
1177 hbinfo.daddr = transport->ipaddr;
1178 hbinfo.sent_at = jiffies;
1179 hbinfo.hb_nonce = transport->hb_nonce;
1180 hbinfo.probe_size = probe_size;
1181
1182 /* Cast away the 'const', as this is just telling the chunk
1183 * what transport it belongs to.
1184 */
1185 retval->transport = (struct sctp_transport *) transport;
1186 retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo),
1187 &hbinfo);
1188 retval->pmtu_probe = !!probe_size;
1189
1190 nodata:
1191 return retval;
1192 }
1193
1194 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc,
1195 const struct sctp_chunk *chunk,
1196 const void *payload,
1197 const size_t paylen)
1198 {
1199 struct sctp_chunk *retval;
1200
1201 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen,
1202 GFP_ATOMIC);
1203 if (!retval)
1204 goto nodata;
1205
1206 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload);
1207
1208 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
1209 *
1210 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1211 * HEARTBEAT ACK, * etc.) to the same destination transport
1212 * address from which it * received the DATA or control chunk
1213 * to which it is replying.
1214 *
1215 * [HBACK back to where the HEARTBEAT came from.]
1216 */
1217 if (chunk)
1218 retval->transport = chunk->transport;
1219
1220 nodata:
1221 return retval;
1222 }
1223
1224 /* RFC4820 3. Padding Chunk (PAD)
1225 * 0 1 2 3
1226 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
1227 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1228 * | Type = 0x84 | Flags=0 | Length |
1229 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1230 * | |
1231 * \ Padding Data /
1232 * / \
1233 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1234 */
1235 struct sctp_chunk *sctp_make_pad(const struct sctp_association *asoc, int len)
1236 {
1237 struct sctp_chunk *retval;
1238
1239 retval = sctp_make_control(asoc, SCTP_CID_PAD, 0, len, GFP_ATOMIC);
1240 if (!retval)
1241 return NULL;
1242
1243 skb_put_zero(retval->skb, len);
1244 retval->chunk_hdr->length = htons(ntohs(retval->chunk_hdr->length) + len);
1245 retval->chunk_end = skb_tail_pointer(retval->skb);
1246
1247 return retval;
1248 }
1249
1250 /* Create an Operation Error chunk with the specified space reserved.
1251 * This routine can be used for containing multiple causes in the chunk.
1252 */
1253 static struct sctp_chunk *sctp_make_op_error_space(
1254 const struct sctp_association *asoc,
1255 const struct sctp_chunk *chunk,
1256 size_t size)
1257 {
1258 struct sctp_chunk *retval;
1259
1260 retval = sctp_make_control(asoc, SCTP_CID_ERROR, 0,
1261 sizeof(struct sctp_errhdr) + size,
1262 GFP_ATOMIC);
1263 if (!retval)
1264 goto nodata;
1265
1266 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
1267 *
1268 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1269 * HEARTBEAT ACK, etc.) to the same destination transport
1270 * address from which it received the DATA or control chunk
1271 * to which it is replying.
1272 *
1273 */
1274 if (chunk)
1275 retval->transport = chunk->transport;
1276
1277 nodata:
1278 return retval;
1279 }
1280
1281 /* Create an Operation Error chunk of a fixed size, specifically,
1282 * min(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT) - overheads.
1283 * This is a helper function to allocate an error chunk for those
1284 * invalid parameter codes in which we may not want to report all the
1285 * errors, if the incoming chunk is large. If it can't fit in a single
1286 * packet, we ignore it.
1287 */
1288 static inline struct sctp_chunk *sctp_make_op_error_limited(
1289 const struct sctp_association *asoc,
1290 const struct sctp_chunk *chunk)
1291 {
1292 size_t size = SCTP_DEFAULT_MAXSEGMENT;
1293 struct sctp_sock *sp = NULL;
1294
1295 if (asoc) {
1296 size = min_t(size_t, size, asoc->pathmtu);
1297 sp = sctp_sk(asoc->base.sk);
1298 }
1299
1300 size = sctp_mtu_payload(sp, size, sizeof(struct sctp_errhdr));
1301
1302 return sctp_make_op_error_space(asoc, chunk, size);
1303 }
1304
1305 /* Create an Operation Error chunk. */
1306 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc,
1307 const struct sctp_chunk *chunk,
1308 __be16 cause_code, const void *payload,
1309 size_t paylen, size_t reserve_tail)
1310 {
1311 struct sctp_chunk *retval;
1312
1313 retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail);
1314 if (!retval)
1315 goto nodata;
1316
1317 sctp_init_cause(retval, cause_code, paylen + reserve_tail);
1318 sctp_addto_chunk(retval, paylen, payload);
1319 if (reserve_tail)
1320 sctp_addto_param(retval, reserve_tail, NULL);
1321
1322 nodata:
1323 return retval;
1324 }
1325
1326 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc,
1327 __u16 key_id)
1328 {
1329 struct sctp_authhdr auth_hdr;
1330 struct sctp_hmac *hmac_desc;
1331 struct sctp_chunk *retval;
1332
1333 /* Get the first hmac that the peer told us to use */
1334 hmac_desc = sctp_auth_asoc_get_hmac(asoc);
1335 if (unlikely(!hmac_desc))
1336 return NULL;
1337
1338 retval = sctp_make_control(asoc, SCTP_CID_AUTH, 0,
1339 hmac_desc->hmac_len + sizeof(auth_hdr),
1340 GFP_ATOMIC);
1341 if (!retval)
1342 return NULL;
1343
1344 auth_hdr.hmac_id = htons(hmac_desc->hmac_id);
1345 auth_hdr.shkey_id = htons(key_id);
1346
1347 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(auth_hdr),
1348 &auth_hdr);
1349
1350 skb_put_zero(retval->skb, hmac_desc->hmac_len);
1351
1352 /* Adjust the chunk header to include the empty MAC */
1353 retval->chunk_hdr->length =
1354 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len);
1355 retval->chunk_end = skb_tail_pointer(retval->skb);
1356
1357 return retval;
1358 }
1359
1360
1361 /********************************************************************
1362 * 2nd Level Abstractions
1363 ********************************************************************/
1364
1365 /* Turn an skb into a chunk.
1366 * FIXME: Eventually move the structure directly inside the skb->cb[].
1367 *
1368 * sctpimpguide-05.txt Section 2.8.2
1369 * M1) Each time a new DATA chunk is transmitted
1370 * set the 'TSN.Missing.Report' count for that TSN to 0. The
1371 * 'TSN.Missing.Report' count will be used to determine missing chunks
1372 * and when to fast retransmit.
1373 *
1374 */
1375 struct sctp_chunk *sctp_chunkify(struct sk_buff *skb,
1376 const struct sctp_association *asoc,
1377 struct sock *sk, gfp_t gfp)
1378 {
1379 struct sctp_chunk *retval;
1380
1381 retval = kmem_cache_zalloc(sctp_chunk_cachep, gfp);
1382
1383 if (!retval)
1384 goto nodata;
1385 if (!sk)
1386 pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb);
1387
1388 INIT_LIST_HEAD(&retval->list);
1389 retval->skb = skb;
1390 retval->asoc = (struct sctp_association *)asoc;
1391 retval->singleton = 1;
1392
1393 retval->fast_retransmit = SCTP_CAN_FRTX;
1394
1395 /* Polish the bead hole. */
1396 INIT_LIST_HEAD(&retval->transmitted_list);
1397 INIT_LIST_HEAD(&retval->frag_list);
1398 SCTP_DBG_OBJCNT_INC(chunk);
1399 refcount_set(&retval->refcnt, 1);
1400
1401 nodata:
1402 return retval;
1403 }
1404
1405 /* Set chunk->source and dest based on the IP header in chunk->skb. */
1406 void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src,
1407 union sctp_addr *dest)
1408 {
1409 memcpy(&chunk->source, src, sizeof(union sctp_addr));
1410 memcpy(&chunk->dest, dest, sizeof(union sctp_addr));
1411 }
1412
1413 /* Extract the source address from a chunk. */
1414 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk)
1415 {
1416 /* If we have a known transport, use that. */
1417 if (chunk->transport) {
1418 return &chunk->transport->ipaddr;
1419 } else {
1420 /* Otherwise, extract it from the IP header. */
1421 return &chunk->source;
1422 }
1423 }
1424
1425 /* Create a new chunk, setting the type and flags headers from the
1426 * arguments, reserving enough space for a 'paylen' byte payload.
1427 */
1428 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc,
1429 __u8 type, __u8 flags, int paylen,
1430 gfp_t gfp)
1431 {
1432 struct sctp_chunkhdr *chunk_hdr;
1433 struct sctp_chunk *retval;
1434 struct sk_buff *skb;
1435 struct sock *sk;
1436 int chunklen;
1437
1438 chunklen = SCTP_PAD4(sizeof(*chunk_hdr) + paylen);
1439 if (chunklen > SCTP_MAX_CHUNK_LEN)
1440 goto nodata;
1441
1442 /* No need to allocate LL here, as this is only a chunk. */
1443 skb = alloc_skb(chunklen, gfp);
1444 if (!skb)
1445 goto nodata;
1446
1447 /* Make room for the chunk header. */
1448 chunk_hdr = (struct sctp_chunkhdr *)skb_put(skb, sizeof(*chunk_hdr));
1449 chunk_hdr->type = type;
1450 chunk_hdr->flags = flags;
1451 chunk_hdr->length = htons(sizeof(*chunk_hdr));
1452
1453 sk = asoc ? asoc->base.sk : NULL;
1454 retval = sctp_chunkify(skb, asoc, sk, gfp);
1455 if (!retval) {
1456 kfree_skb(skb);
1457 goto nodata;
1458 }
1459
1460 retval->chunk_hdr = chunk_hdr;
1461 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(*chunk_hdr);
1462
1463 /* Determine if the chunk needs to be authenticated */
1464 if (sctp_auth_send_cid(type, asoc))
1465 retval->auth = 1;
1466
1467 return retval;
1468 nodata:
1469 return NULL;
1470 }
1471
1472 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc,
1473 __u8 flags, int paylen, gfp_t gfp)
1474 {
1475 return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen, gfp);
1476 }
1477
1478 struct sctp_chunk *sctp_make_idata(const struct sctp_association *asoc,
1479 __u8 flags, int paylen, gfp_t gfp)
1480 {
1481 return _sctp_make_chunk(asoc, SCTP_CID_I_DATA, flags, paylen, gfp);
1482 }
1483
1484 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc,
1485 __u8 type, __u8 flags, int paylen,
1486 gfp_t gfp)
1487 {
1488 struct sctp_chunk *chunk;
1489
1490 chunk = _sctp_make_chunk(asoc, type, flags, paylen, gfp);
1491 if (chunk)
1492 sctp_control_set_owner_w(chunk);
1493
1494 return chunk;
1495 }
1496
1497 /* Release the memory occupied by a chunk. */
1498 static void sctp_chunk_destroy(struct sctp_chunk *chunk)
1499 {
1500 BUG_ON(!list_empty(&chunk->list));
1501 list_del_init(&chunk->transmitted_list);
1502
1503 consume_skb(chunk->skb);
1504 consume_skb(chunk->auth_chunk);
1505
1506 SCTP_DBG_OBJCNT_DEC(chunk);
1507 kmem_cache_free(sctp_chunk_cachep, chunk);
1508 }
1509
1510 /* Possibly, free the chunk. */
1511 void sctp_chunk_free(struct sctp_chunk *chunk)
1512 {
1513 /* Release our reference on the message tracker. */
1514 if (chunk->msg)
1515 sctp_datamsg_put(chunk->msg);
1516
1517 sctp_chunk_put(chunk);
1518 }
1519
1520 /* Grab a reference to the chunk. */
1521 void sctp_chunk_hold(struct sctp_chunk *ch)
1522 {
1523 refcount_inc(&ch->refcnt);
1524 }
1525
1526 /* Release a reference to the chunk. */
1527 void sctp_chunk_put(struct sctp_chunk *ch)
1528 {
1529 if (refcount_dec_and_test(&ch->refcnt))
1530 sctp_chunk_destroy(ch);
1531 }
1532
1533 /* Append bytes to the end of a chunk. Will panic if chunk is not big
1534 * enough.
1535 */
1536 void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data)
1537 {
1538 int chunklen = ntohs(chunk->chunk_hdr->length);
1539 int padlen = SCTP_PAD4(chunklen) - chunklen;
1540 void *target;
1541
1542 skb_put_zero(chunk->skb, padlen);
1543 target = skb_put_data(chunk->skb, data, len);
1544
1545 /* Adjust the chunk length field. */
1546 chunk->chunk_hdr->length = htons(chunklen + padlen + len);
1547 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1548
1549 return target;
1550 }
1551
1552 /* Append bytes from user space to the end of a chunk. Will panic if
1553 * chunk is not big enough.
1554 * Returns a kernel err value.
1555 */
1556 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
1557 struct iov_iter *from)
1558 {
1559 void *target;
1560
1561 /* Make room in chunk for data. */
1562 target = skb_put(chunk->skb, len);
1563
1564 /* Copy data (whole iovec) into chunk */
1565 if (!copy_from_iter_full(target, len, from))
1566 return -EFAULT;
1567
1568 /* Adjust the chunk length field. */
1569 chunk->chunk_hdr->length =
1570 htons(ntohs(chunk->chunk_hdr->length) + len);
1571 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1572
1573 return 0;
1574 }
1575
1576 /* Helper function to assign a TSN if needed. This assumes that both
1577 * the data_hdr and association have already been assigned.
1578 */
1579 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk)
1580 {
1581 struct sctp_stream *stream;
1582 struct sctp_chunk *lchunk;
1583 struct sctp_datamsg *msg;
1584 __u16 ssn, sid;
1585
1586 if (chunk->has_ssn)
1587 return;
1588
1589 /* All fragments will be on the same stream */
1590 sid = ntohs(chunk->subh.data_hdr->stream);
1591 stream = &chunk->asoc->stream;
1592
1593 /* Now assign the sequence number to the entire message.
1594 * All fragments must have the same stream sequence number.
1595 */
1596 msg = chunk->msg;
1597 list_for_each_entry(lchunk, &msg->chunks, frag_list) {
1598 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
1599 ssn = 0;
1600 } else {
1601 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG)
1602 ssn = sctp_ssn_next(stream, out, sid);
1603 else
1604 ssn = sctp_ssn_peek(stream, out, sid);
1605 }
1606
1607 lchunk->subh.data_hdr->ssn = htons(ssn);
1608 lchunk->has_ssn = 1;
1609 }
1610 }
1611
1612 /* Helper function to assign a TSN if needed. This assumes that both
1613 * the data_hdr and association have already been assigned.
1614 */
1615 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk)
1616 {
1617 if (!chunk->has_tsn) {
1618 /* This is the last possible instant to
1619 * assign a TSN.
1620 */
1621 chunk->subh.data_hdr->tsn =
1622 htonl(sctp_association_get_next_tsn(chunk->asoc));
1623 chunk->has_tsn = 1;
1624 }
1625 }
1626
1627 /* Create a CLOSED association to use with an incoming packet. */
1628 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep,
1629 struct sctp_chunk *chunk,
1630 gfp_t gfp)
1631 {
1632 struct sctp_association *asoc;
1633 enum sctp_scope scope;
1634 struct sk_buff *skb;
1635
1636 /* Create the bare association. */
1637 scope = sctp_scope(sctp_source(chunk));
1638 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp);
1639 if (!asoc)
1640 goto nodata;
1641 asoc->temp = 1;
1642 skb = chunk->skb;
1643 /* Create an entry for the source address of the packet. */
1644 SCTP_INPUT_CB(skb)->af->from_skb(&asoc->c.peer_addr, skb, 1);
1645
1646 nodata:
1647 return asoc;
1648 }
1649
1650 /* Build a cookie representing asoc.
1651 * This INCLUDES the param header needed to put the cookie in the INIT ACK.
1652 */
1653 static struct sctp_cookie_param *sctp_pack_cookie(
1654 const struct sctp_endpoint *ep,
1655 const struct sctp_association *asoc,
1656 const struct sctp_chunk *init_chunk,
1657 int *cookie_len, const __u8 *raw_addrs,
1658 int addrs_len)
1659 {
1660 struct sctp_signed_cookie *cookie;
1661 struct sctp_cookie_param *retval;
1662 int headersize, bodysize;
1663
1664 /* Header size is static data prior to the actual cookie, including
1665 * any padding.
1666 */
1667 headersize = sizeof(struct sctp_paramhdr) +
1668 (sizeof(struct sctp_signed_cookie) -
1669 sizeof(struct sctp_cookie));
1670 bodysize = sizeof(struct sctp_cookie)
1671 + ntohs(init_chunk->chunk_hdr->length) + addrs_len;
1672
1673 /* Pad out the cookie to a multiple to make the signature
1674 * functions simpler to write.
1675 */
1676 if (bodysize % SCTP_COOKIE_MULTIPLE)
1677 bodysize += SCTP_COOKIE_MULTIPLE
1678 - (bodysize % SCTP_COOKIE_MULTIPLE);
1679 *cookie_len = headersize + bodysize;
1680
1681 /* Clear this memory since we are sending this data structure
1682 * out on the network.
1683 */
1684 retval = kzalloc(*cookie_len, GFP_ATOMIC);
1685 if (!retval)
1686 goto nodata;
1687
1688 cookie = (struct sctp_signed_cookie *) retval->body;
1689
1690 /* Set up the parameter header. */
1691 retval->p.type = SCTP_PARAM_STATE_COOKIE;
1692 retval->p.length = htons(*cookie_len);
1693
1694 /* Copy the cookie part of the association itself. */
1695 cookie->c = asoc->c;
1696 /* Save the raw address list length in the cookie. */
1697 cookie->c.raw_addr_list_len = addrs_len;
1698
1699 /* Remember PR-SCTP capability. */
1700 cookie->c.prsctp_capable = asoc->peer.prsctp_capable;
1701
1702 /* Save adaptation indication in the cookie. */
1703 cookie->c.adaptation_ind = asoc->peer.adaptation_ind;
1704
1705 /* Set an expiration time for the cookie. */
1706 cookie->c.expiration = ktime_add(asoc->cookie_life,
1707 ktime_get_real());
1708
1709 /* Copy the peer's init packet. */
1710 memcpy(cookie + 1, init_chunk->chunk_hdr,
1711 ntohs(init_chunk->chunk_hdr->length));
1712
1713 /* Copy the raw local address list of the association. */
1714 memcpy((__u8 *)(cookie + 1) +
1715 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len);
1716
1717 if (sctp_sk(ep->base.sk)->hmac) {
1718 struct crypto_shash *tfm = sctp_sk(ep->base.sk)->hmac;
1719 int err;
1720
1721 /* Sign the message. */
1722 err = crypto_shash_setkey(tfm, ep->secret_key,
1723 sizeof(ep->secret_key)) ?:
1724 crypto_shash_tfm_digest(tfm, (u8 *)&cookie->c, bodysize,
1725 cookie->signature);
1726 if (err)
1727 goto free_cookie;
1728 }
1729
1730 return retval;
1731
1732 free_cookie:
1733 kfree(retval);
1734 nodata:
1735 *cookie_len = 0;
1736 return NULL;
1737 }
1738
1739 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */
1740 struct sctp_association *sctp_unpack_cookie(
1741 const struct sctp_endpoint *ep,
1742 const struct sctp_association *asoc,
1743 struct sctp_chunk *chunk, gfp_t gfp,
1744 int *error, struct sctp_chunk **errp)
1745 {
1746 struct sctp_association *retval = NULL;
1747 int headersize, bodysize, fixed_size;
1748 struct sctp_signed_cookie *cookie;
1749 struct sk_buff *skb = chunk->skb;
1750 struct sctp_cookie *bear_cookie;
1751 __u8 *digest = ep->digest;
1752 enum sctp_scope scope;
1753 unsigned int len;
1754 ktime_t kt;
1755
1756 /* Header size is static data prior to the actual cookie, including
1757 * any padding.
1758 */
1759 headersize = sizeof(struct sctp_chunkhdr) +
1760 (sizeof(struct sctp_signed_cookie) -
1761 sizeof(struct sctp_cookie));
1762 bodysize = ntohs(chunk->chunk_hdr->length) - headersize;
1763 fixed_size = headersize + sizeof(struct sctp_cookie);
1764
1765 /* Verify that the chunk looks like it even has a cookie.
1766 * There must be enough room for our cookie and our peer's
1767 * INIT chunk.
1768 */
1769 len = ntohs(chunk->chunk_hdr->length);
1770 if (len < fixed_size + sizeof(struct sctp_chunkhdr))
1771 goto malformed;
1772
1773 /* Verify that the cookie has been padded out. */
1774 if (bodysize % SCTP_COOKIE_MULTIPLE)
1775 goto malformed;
1776
1777 /* Process the cookie. */
1778 cookie = chunk->subh.cookie_hdr;
1779 bear_cookie = &cookie->c;
1780
1781 if (!sctp_sk(ep->base.sk)->hmac)
1782 goto no_hmac;
1783
1784 /* Check the signature. */
1785 {
1786 struct crypto_shash *tfm = sctp_sk(ep->base.sk)->hmac;
1787 int err;
1788
1789 err = crypto_shash_setkey(tfm, ep->secret_key,
1790 sizeof(ep->secret_key)) ?:
1791 crypto_shash_tfm_digest(tfm, (u8 *)bear_cookie, bodysize,
1792 digest);
1793 if (err) {
1794 *error = -SCTP_IERROR_NOMEM;
1795 goto fail;
1796 }
1797 }
1798
1799 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
1800 *error = -SCTP_IERROR_BAD_SIG;
1801 goto fail;
1802 }
1803
1804 no_hmac:
1805 /* IG Section 2.35.2:
1806 * 3) Compare the port numbers and the verification tag contained
1807 * within the COOKIE ECHO chunk to the actual port numbers and the
1808 * verification tag within the SCTP common header of the received
1809 * packet. If these values do not match the packet MUST be silently
1810 * discarded,
1811 */
1812 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) {
1813 *error = -SCTP_IERROR_BAD_TAG;
1814 goto fail;
1815 }
1816
1817 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port ||
1818 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) {
1819 *error = -SCTP_IERROR_BAD_PORTS;
1820 goto fail;
1821 }
1822
1823 /* Check to see if the cookie is stale. If there is already
1824 * an association, there is no need to check cookie's expiration
1825 * for init collision case of lost COOKIE ACK.
1826 * If skb has been timestamped, then use the stamp, otherwise
1827 * use current time. This introduces a small possibility that
1828 * a cookie may be considered expired, but this would only slow
1829 * down the new association establishment instead of every packet.
1830 */
1831 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP))
1832 kt = skb_get_ktime(skb);
1833 else
1834 kt = ktime_get_real();
1835
1836 if (!asoc && ktime_before(bear_cookie->expiration, kt)) {
1837 suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration));
1838 __be32 n = htonl(usecs);
1839
1840 /*
1841 * Section 3.3.10.3 Stale Cookie Error (3)
1842 *
1843 * Cause of error
1844 * ---------------
1845 * Stale Cookie Error: Indicates the receipt of a valid State
1846 * Cookie that has expired.
1847 */
1848 *errp = sctp_make_op_error(asoc, chunk,
1849 SCTP_ERROR_STALE_COOKIE, &n,
1850 sizeof(n), 0);
1851 if (*errp)
1852 *error = -SCTP_IERROR_STALE_COOKIE;
1853 else
1854 *error = -SCTP_IERROR_NOMEM;
1855
1856 goto fail;
1857 }
1858
1859 /* Make a new base association. */
1860 scope = sctp_scope(sctp_source(chunk));
1861 retval = sctp_association_new(ep, ep->base.sk, scope, gfp);
1862 if (!retval) {
1863 *error = -SCTP_IERROR_NOMEM;
1864 goto fail;
1865 }
1866
1867 /* Set up our peer's port number. */
1868 retval->peer.port = ntohs(chunk->sctp_hdr->source);
1869
1870 /* Populate the association from the cookie. */
1871 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie));
1872
1873 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie,
1874 GFP_ATOMIC) < 0) {
1875 *error = -SCTP_IERROR_NOMEM;
1876 goto fail;
1877 }
1878
1879 /* Also, add the destination address. */
1880 if (list_empty(&retval->base.bind_addr.address_list)) {
1881 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest,
1882 sizeof(chunk->dest), SCTP_ADDR_SRC,
1883 GFP_ATOMIC);
1884 }
1885
1886 retval->next_tsn = retval->c.initial_tsn;
1887 retval->ctsn_ack_point = retval->next_tsn - 1;
1888 retval->addip_serial = retval->c.initial_tsn;
1889 retval->strreset_outseq = retval->c.initial_tsn;
1890 retval->adv_peer_ack_point = retval->ctsn_ack_point;
1891 retval->peer.prsctp_capable = retval->c.prsctp_capable;
1892 retval->peer.adaptation_ind = retval->c.adaptation_ind;
1893
1894 /* The INIT stuff will be done by the side effects. */
1895 return retval;
1896
1897 fail:
1898 if (retval)
1899 sctp_association_free(retval);
1900
1901 return NULL;
1902
1903 malformed:
1904 /* Yikes! The packet is either corrupt or deliberately
1905 * malformed.
1906 */
1907 *error = -SCTP_IERROR_MALFORMED;
1908 goto fail;
1909 }
1910
1911 /********************************************************************
1912 * 3rd Level Abstractions
1913 ********************************************************************/
1914
1915 struct __sctp_missing {
1916 __be32 num_missing;
1917 __be16 type;
1918 } __packed;
1919
1920 /*
1921 * Report a missing mandatory parameter.
1922 */
1923 static int sctp_process_missing_param(const struct sctp_association *asoc,
1924 enum sctp_param paramtype,
1925 struct sctp_chunk *chunk,
1926 struct sctp_chunk **errp)
1927 {
1928 struct __sctp_missing report;
1929 __u16 len;
1930
1931 len = SCTP_PAD4(sizeof(report));
1932
1933 /* Make an ERROR chunk, preparing enough room for
1934 * returning multiple unknown parameters.
1935 */
1936 if (!*errp)
1937 *errp = sctp_make_op_error_space(asoc, chunk, len);
1938
1939 if (*errp) {
1940 report.num_missing = htonl(1);
1941 report.type = paramtype;
1942 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM,
1943 sizeof(report));
1944 sctp_addto_chunk(*errp, sizeof(report), &report);
1945 }
1946
1947 /* Stop processing this chunk. */
1948 return 0;
1949 }
1950
1951 /* Report an Invalid Mandatory Parameter. */
1952 static int sctp_process_inv_mandatory(const struct sctp_association *asoc,
1953 struct sctp_chunk *chunk,
1954 struct sctp_chunk **errp)
1955 {
1956 /* Invalid Mandatory Parameter Error has no payload. */
1957
1958 if (!*errp)
1959 *errp = sctp_make_op_error_space(asoc, chunk, 0);
1960
1961 if (*errp)
1962 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0);
1963
1964 /* Stop processing this chunk. */
1965 return 0;
1966 }
1967
1968 static int sctp_process_inv_paramlength(const struct sctp_association *asoc,
1969 struct sctp_paramhdr *param,
1970 const struct sctp_chunk *chunk,
1971 struct sctp_chunk **errp)
1972 {
1973 /* This is a fatal error. Any accumulated non-fatal errors are
1974 * not reported.
1975 */
1976 if (*errp)
1977 sctp_chunk_free(*errp);
1978
1979 /* Create an error chunk and fill it in with our payload. */
1980 *errp = sctp_make_violation_paramlen(asoc, chunk, param);
1981
1982 return 0;
1983 }
1984
1985
1986 /* Do not attempt to handle the HOST_NAME parm. However, do
1987 * send back an indicator to the peer.
1988 */
1989 static int sctp_process_hn_param(const struct sctp_association *asoc,
1990 union sctp_params param,
1991 struct sctp_chunk *chunk,
1992 struct sctp_chunk **errp)
1993 {
1994 __u16 len = ntohs(param.p->length);
1995
1996 /* Processing of the HOST_NAME parameter will generate an
1997 * ABORT. If we've accumulated any non-fatal errors, they
1998 * would be unrecognized parameters and we should not include
1999 * them in the ABORT.
2000 */
2001 if (*errp)
2002 sctp_chunk_free(*errp);
2003
2004 *errp = sctp_make_op_error(asoc, chunk, SCTP_ERROR_DNS_FAILED,
2005 param.v, len, 0);
2006
2007 /* Stop processing this chunk. */
2008 return 0;
2009 }
2010
2011 static int sctp_verify_ext_param(struct net *net,
2012 const struct sctp_endpoint *ep,
2013 union sctp_params param)
2014 {
2015 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
2016 int have_asconf = 0;
2017 int have_auth = 0;
2018 int i;
2019
2020 for (i = 0; i < num_ext; i++) {
2021 switch (param.ext->chunks[i]) {
2022 case SCTP_CID_AUTH:
2023 have_auth = 1;
2024 break;
2025 case SCTP_CID_ASCONF:
2026 case SCTP_CID_ASCONF_ACK:
2027 have_asconf = 1;
2028 break;
2029 }
2030 }
2031
2032 /* ADD-IP Security: The draft requires us to ABORT or ignore the
2033 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this
2034 * only if ADD-IP is turned on and we are not backward-compatible
2035 * mode.
2036 */
2037 if (net->sctp.addip_noauth)
2038 return 1;
2039
2040 if (ep->asconf_enable && !have_auth && have_asconf)
2041 return 0;
2042
2043 return 1;
2044 }
2045
2046 static void sctp_process_ext_param(struct sctp_association *asoc,
2047 union sctp_params param)
2048 {
2049 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
2050 int i;
2051
2052 for (i = 0; i < num_ext; i++) {
2053 switch (param.ext->chunks[i]) {
2054 case SCTP_CID_RECONF:
2055 if (asoc->ep->reconf_enable)
2056 asoc->peer.reconf_capable = 1;
2057 break;
2058 case SCTP_CID_FWD_TSN:
2059 if (asoc->ep->prsctp_enable)
2060 asoc->peer.prsctp_capable = 1;
2061 break;
2062 case SCTP_CID_AUTH:
2063 /* if the peer reports AUTH, assume that he
2064 * supports AUTH.
2065 */
2066 if (asoc->ep->auth_enable)
2067 asoc->peer.auth_capable = 1;
2068 break;
2069 case SCTP_CID_ASCONF:
2070 case SCTP_CID_ASCONF_ACK:
2071 if (asoc->ep->asconf_enable)
2072 asoc->peer.asconf_capable = 1;
2073 break;
2074 case SCTP_CID_I_DATA:
2075 if (asoc->ep->intl_enable)
2076 asoc->peer.intl_capable = 1;
2077 break;
2078 default:
2079 break;
2080 }
2081 }
2082 }
2083
2084 /* RFC 3.2.1 & the Implementers Guide 2.2.
2085 *
2086 * The Parameter Types are encoded such that the
2087 * highest-order two bits specify the action that must be
2088 * taken if the processing endpoint does not recognize the
2089 * Parameter Type.
2090 *
2091 * 00 - Stop processing this parameter; do not process any further
2092 * parameters within this chunk
2093 *
2094 * 01 - Stop processing this parameter, do not process any further
2095 * parameters within this chunk, and report the unrecognized
2096 * parameter in an 'Unrecognized Parameter' ERROR chunk.
2097 *
2098 * 10 - Skip this parameter and continue processing.
2099 *
2100 * 11 - Skip this parameter and continue processing but
2101 * report the unrecognized parameter in an
2102 * 'Unrecognized Parameter' ERROR chunk.
2103 *
2104 * Return value:
2105 * SCTP_IERROR_NO_ERROR - continue with the chunk
2106 * SCTP_IERROR_ERROR - stop and report an error.
2107 * SCTP_IERROR_NOMEME - out of memory.
2108 */
2109 static enum sctp_ierror sctp_process_unk_param(
2110 const struct sctp_association *asoc,
2111 union sctp_params param,
2112 struct sctp_chunk *chunk,
2113 struct sctp_chunk **errp)
2114 {
2115 int retval = SCTP_IERROR_NO_ERROR;
2116
2117 switch (param.p->type & SCTP_PARAM_ACTION_MASK) {
2118 case SCTP_PARAM_ACTION_DISCARD:
2119 retval = SCTP_IERROR_ERROR;
2120 break;
2121 case SCTP_PARAM_ACTION_SKIP:
2122 break;
2123 case SCTP_PARAM_ACTION_DISCARD_ERR:
2124 retval = SCTP_IERROR_ERROR;
2125 fallthrough;
2126 case SCTP_PARAM_ACTION_SKIP_ERR:
2127 /* Make an ERROR chunk, preparing enough room for
2128 * returning multiple unknown parameters.
2129 */
2130 if (!*errp) {
2131 *errp = sctp_make_op_error_limited(asoc, chunk);
2132 if (!*errp) {
2133 /* If there is no memory for generating the
2134 * ERROR report as specified, an ABORT will be
2135 * triggered to the peer and the association
2136 * won't be established.
2137 */
2138 retval = SCTP_IERROR_NOMEM;
2139 break;
2140 }
2141 }
2142
2143 if (!sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM,
2144 ntohs(param.p->length)))
2145 sctp_addto_chunk(*errp, ntohs(param.p->length),
2146 param.v);
2147 break;
2148 default:
2149 break;
2150 }
2151
2152 return retval;
2153 }
2154
2155 /* Verify variable length parameters
2156 * Return values:
2157 * SCTP_IERROR_ABORT - trigger an ABORT
2158 * SCTP_IERROR_NOMEM - out of memory (abort)
2159 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR
2160 * SCTP_IERROR_NO_ERROR - continue with the chunk
2161 */
2162 static enum sctp_ierror sctp_verify_param(struct net *net,
2163 const struct sctp_endpoint *ep,
2164 const struct sctp_association *asoc,
2165 union sctp_params param,
2166 enum sctp_cid cid,
2167 struct sctp_chunk *chunk,
2168 struct sctp_chunk **err_chunk)
2169 {
2170 struct sctp_hmac_algo_param *hmacs;
2171 int retval = SCTP_IERROR_NO_ERROR;
2172 __u16 n_elt, id = 0;
2173 int i;
2174
2175 /* FIXME - This routine is not looking at each parameter per the
2176 * chunk type, i.e., unrecognized parameters should be further
2177 * identified based on the chunk id.
2178 */
2179
2180 switch (param.p->type) {
2181 case SCTP_PARAM_IPV4_ADDRESS:
2182 case SCTP_PARAM_IPV6_ADDRESS:
2183 case SCTP_PARAM_COOKIE_PRESERVATIVE:
2184 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
2185 case SCTP_PARAM_STATE_COOKIE:
2186 case SCTP_PARAM_HEARTBEAT_INFO:
2187 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
2188 case SCTP_PARAM_ECN_CAPABLE:
2189 case SCTP_PARAM_ADAPTATION_LAYER_IND:
2190 break;
2191
2192 case SCTP_PARAM_SUPPORTED_EXT:
2193 if (!sctp_verify_ext_param(net, ep, param))
2194 return SCTP_IERROR_ABORT;
2195 break;
2196
2197 case SCTP_PARAM_SET_PRIMARY:
2198 if (!ep->asconf_enable)
2199 goto unhandled;
2200
2201 if (ntohs(param.p->length) < sizeof(struct sctp_addip_param) +
2202 sizeof(struct sctp_paramhdr)) {
2203 sctp_process_inv_paramlength(asoc, param.p,
2204 chunk, err_chunk);
2205 retval = SCTP_IERROR_ABORT;
2206 }
2207 break;
2208
2209 case SCTP_PARAM_HOST_NAME_ADDRESS:
2210 /* This param has been Deprecated, send ABORT. */
2211 sctp_process_hn_param(asoc, param, chunk, err_chunk);
2212 retval = SCTP_IERROR_ABORT;
2213 break;
2214
2215 case SCTP_PARAM_FWD_TSN_SUPPORT:
2216 if (ep->prsctp_enable)
2217 break;
2218 goto unhandled;
2219
2220 case SCTP_PARAM_RANDOM:
2221 if (!ep->auth_enable)
2222 goto unhandled;
2223
2224 /* SCTP-AUTH: Secion 6.1
2225 * If the random number is not 32 byte long the association
2226 * MUST be aborted. The ABORT chunk SHOULD contain the error
2227 * cause 'Protocol Violation'.
2228 */
2229 if (SCTP_AUTH_RANDOM_LENGTH != ntohs(param.p->length) -
2230 sizeof(struct sctp_paramhdr)) {
2231 sctp_process_inv_paramlength(asoc, param.p,
2232 chunk, err_chunk);
2233 retval = SCTP_IERROR_ABORT;
2234 }
2235 break;
2236
2237 case SCTP_PARAM_CHUNKS:
2238 if (!ep->auth_enable)
2239 goto unhandled;
2240
2241 /* SCTP-AUTH: Section 3.2
2242 * The CHUNKS parameter MUST be included once in the INIT or
2243 * INIT-ACK chunk if the sender wants to receive authenticated
2244 * chunks. Its maximum length is 260 bytes.
2245 */
2246 if (260 < ntohs(param.p->length)) {
2247 sctp_process_inv_paramlength(asoc, param.p,
2248 chunk, err_chunk);
2249 retval = SCTP_IERROR_ABORT;
2250 }
2251 break;
2252
2253 case SCTP_PARAM_HMAC_ALGO:
2254 if (!ep->auth_enable)
2255 goto unhandled;
2256
2257 hmacs = (struct sctp_hmac_algo_param *)param.p;
2258 n_elt = (ntohs(param.p->length) -
2259 sizeof(struct sctp_paramhdr)) >> 1;
2260
2261 /* SCTP-AUTH: Section 6.1
2262 * The HMAC algorithm based on SHA-1 MUST be supported and
2263 * included in the HMAC-ALGO parameter.
2264 */
2265 for (i = 0; i < n_elt; i++) {
2266 id = ntohs(hmacs->hmac_ids[i]);
2267
2268 if (id == SCTP_AUTH_HMAC_ID_SHA1)
2269 break;
2270 }
2271
2272 if (id != SCTP_AUTH_HMAC_ID_SHA1) {
2273 sctp_process_inv_paramlength(asoc, param.p, chunk,
2274 err_chunk);
2275 retval = SCTP_IERROR_ABORT;
2276 }
2277 break;
2278 unhandled:
2279 default:
2280 pr_debug("%s: unrecognized param:%d for chunk:%d\n",
2281 __func__, ntohs(param.p->type), cid);
2282
2283 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk);
2284 break;
2285 }
2286 return retval;
2287 }
2288
2289 /* Verify the INIT packet before we process it. */
2290 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
2291 const struct sctp_association *asoc, enum sctp_cid cid,
2292 struct sctp_init_chunk *peer_init,
2293 struct sctp_chunk *chunk, struct sctp_chunk **errp)
2294 {
2295 union sctp_params param;
2296 bool has_cookie = false;
2297 int result;
2298
2299 /* Check for missing mandatory parameters. Note: Initial TSN is
2300 * also mandatory, but is not checked here since the valid range
2301 * is 0..2**32-1. RFC4960, section 3.3.3.
2302 */
2303 if (peer_init->init_hdr.num_outbound_streams == 0 ||
2304 peer_init->init_hdr.num_inbound_streams == 0 ||
2305 peer_init->init_hdr.init_tag == 0 ||
2306 ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW)
2307 return sctp_process_inv_mandatory(asoc, chunk, errp);
2308
2309 sctp_walk_params(param, peer_init) {
2310 if (param.p->type == SCTP_PARAM_STATE_COOKIE)
2311 has_cookie = true;
2312 }
2313
2314 /* There is a possibility that a parameter length was bad and
2315 * in that case we would have stoped walking the parameters.
2316 * The current param.p would point at the bad one.
2317 * Current consensus on the mailing list is to generate a PROTOCOL
2318 * VIOLATION error. We build the ERROR chunk here and let the normal
2319 * error handling code build and send the packet.
2320 */
2321 if (param.v != (void *)chunk->chunk_end)
2322 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp);
2323
2324 /* The only missing mandatory param possible today is
2325 * the state cookie for an INIT-ACK chunk.
2326 */
2327 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie)
2328 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE,
2329 chunk, errp);
2330
2331 /* Verify all the variable length parameters */
2332 sctp_walk_params(param, peer_init) {
2333 result = sctp_verify_param(net, ep, asoc, param, cid,
2334 chunk, errp);
2335 switch (result) {
2336 case SCTP_IERROR_ABORT:
2337 case SCTP_IERROR_NOMEM:
2338 return 0;
2339 case SCTP_IERROR_ERROR:
2340 return 1;
2341 case SCTP_IERROR_NO_ERROR:
2342 default:
2343 break;
2344 }
2345
2346 } /* for (loop through all parameters) */
2347
2348 return 1;
2349 }
2350
2351 /* Unpack the parameters in an INIT packet into an association.
2352 * Returns 0 on failure, else success.
2353 * FIXME: This is an association method.
2354 */
2355 int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk,
2356 const union sctp_addr *peer_addr,
2357 struct sctp_init_chunk *peer_init, gfp_t gfp)
2358 {
2359 struct sctp_transport *transport;
2360 struct list_head *pos, *temp;
2361 union sctp_params param;
2362 union sctp_addr addr;
2363 struct sctp_af *af;
2364 int src_match = 0;
2365
2366 /* We must include the address that the INIT packet came from.
2367 * This is the only address that matters for an INIT packet.
2368 * When processing a COOKIE ECHO, we retrieve the from address
2369 * of the INIT from the cookie.
2370 */
2371
2372 /* This implementation defaults to making the first transport
2373 * added as the primary transport. The source address seems to
2374 * be a better choice than any of the embedded addresses.
2375 */
2376 asoc->encap_port = SCTP_INPUT_CB(chunk->skb)->encap_port;
2377 if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE))
2378 goto nomem;
2379
2380 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr))
2381 src_match = 1;
2382
2383 /* Process the initialization parameters. */
2384 sctp_walk_params(param, peer_init) {
2385 if (!src_match &&
2386 (param.p->type == SCTP_PARAM_IPV4_ADDRESS ||
2387 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) {
2388 af = sctp_get_af_specific(param_type2af(param.p->type));
2389 if (!af->from_addr_param(&addr, param.addr,
2390 chunk->sctp_hdr->source, 0))
2391 continue;
2392 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr))
2393 src_match = 1;
2394 }
2395
2396 if (!sctp_process_param(asoc, param, peer_addr, gfp))
2397 goto clean_up;
2398 }
2399
2400 /* source address of chunk may not match any valid address */
2401 if (!src_match)
2402 goto clean_up;
2403
2404 /* AUTH: After processing the parameters, make sure that we
2405 * have all the required info to potentially do authentications.
2406 */
2407 if (asoc->peer.auth_capable && (!asoc->peer.peer_random ||
2408 !asoc->peer.peer_hmacs))
2409 asoc->peer.auth_capable = 0;
2410
2411 /* In a non-backward compatible mode, if the peer claims
2412 * support for ADD-IP but not AUTH, the ADD-IP spec states
2413 * that we MUST ABORT the association. Section 6. The section
2414 * also give us an option to silently ignore the packet, which
2415 * is what we'll do here.
2416 */
2417 if (!asoc->base.net->sctp.addip_noauth &&
2418 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) {
2419 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP |
2420 SCTP_PARAM_DEL_IP |
2421 SCTP_PARAM_SET_PRIMARY);
2422 asoc->peer.asconf_capable = 0;
2423 goto clean_up;
2424 }
2425
2426 /* Walk list of transports, removing transports in the UNKNOWN state. */
2427 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
2428 transport = list_entry(pos, struct sctp_transport, transports);
2429 if (transport->state == SCTP_UNKNOWN) {
2430 sctp_assoc_rm_peer(asoc, transport);
2431 }
2432 }
2433
2434 /* The fixed INIT headers are always in network byte
2435 * order.
2436 */
2437 asoc->peer.i.init_tag =
2438 ntohl(peer_init->init_hdr.init_tag);
2439 asoc->peer.i.a_rwnd =
2440 ntohl(peer_init->init_hdr.a_rwnd);
2441 asoc->peer.i.num_outbound_streams =
2442 ntohs(peer_init->init_hdr.num_outbound_streams);
2443 asoc->peer.i.num_inbound_streams =
2444 ntohs(peer_init->init_hdr.num_inbound_streams);
2445 asoc->peer.i.initial_tsn =
2446 ntohl(peer_init->init_hdr.initial_tsn);
2447
2448 asoc->strreset_inseq = asoc->peer.i.initial_tsn;
2449
2450 /* Apply the upper bounds for output streams based on peer's
2451 * number of inbound streams.
2452 */
2453 if (asoc->c.sinit_num_ostreams >
2454 ntohs(peer_init->init_hdr.num_inbound_streams)) {
2455 asoc->c.sinit_num_ostreams =
2456 ntohs(peer_init->init_hdr.num_inbound_streams);
2457 }
2458
2459 if (asoc->c.sinit_max_instreams >
2460 ntohs(peer_init->init_hdr.num_outbound_streams)) {
2461 asoc->c.sinit_max_instreams =
2462 ntohs(peer_init->init_hdr.num_outbound_streams);
2463 }
2464
2465 /* Copy Initiation tag from INIT to VT_peer in cookie. */
2466 asoc->c.peer_vtag = asoc->peer.i.init_tag;
2467
2468 /* Peer Rwnd : Current calculated value of the peer's rwnd. */
2469 asoc->peer.rwnd = asoc->peer.i.a_rwnd;
2470
2471 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily
2472 * high (for example, implementations MAY use the size of the receiver
2473 * advertised window).
2474 */
2475 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
2476 transports) {
2477 transport->ssthresh = asoc->peer.i.a_rwnd;
2478 }
2479
2480 /* Set up the TSN tracking pieces. */
2481 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
2482 asoc->peer.i.initial_tsn, gfp))
2483 goto clean_up;
2484
2485 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
2486 *
2487 * The stream sequence number in all the streams shall start
2488 * from 0 when the association is established. Also, when the
2489 * stream sequence number reaches the value 65535 the next
2490 * stream sequence number shall be set to 0.
2491 */
2492
2493 if (sctp_stream_init(&asoc->stream, asoc->c.sinit_num_ostreams,
2494 asoc->c.sinit_max_instreams, gfp))
2495 goto clean_up;
2496
2497 /* Update frag_point when stream_interleave may get changed. */
2498 sctp_assoc_update_frag_point(asoc);
2499
2500 if (!asoc->temp && sctp_assoc_set_id(asoc, gfp))
2501 goto clean_up;
2502
2503 /* ADDIP Section 4.1 ASCONF Chunk Procedures
2504 *
2505 * When an endpoint has an ASCONF signaled change to be sent to the
2506 * remote endpoint it should do the following:
2507 * ...
2508 * A2) A serial number should be assigned to the Chunk. The serial
2509 * number should be a monotonically increasing number. All serial
2510 * numbers are defined to be initialized at the start of the
2511 * association to the same value as the Initial TSN.
2512 */
2513 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1;
2514 return 1;
2515
2516 clean_up:
2517 /* Release the transport structures. */
2518 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
2519 transport = list_entry(pos, struct sctp_transport, transports);
2520 if (transport->state != SCTP_ACTIVE)
2521 sctp_assoc_rm_peer(asoc, transport);
2522 }
2523
2524 nomem:
2525 return 0;
2526 }
2527
2528
2529 /* Update asoc with the option described in param.
2530 *
2531 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT
2532 *
2533 * asoc is the association to update.
2534 * param is the variable length parameter to use for update.
2535 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO.
2536 * If the current packet is an INIT we want to minimize the amount of
2537 * work we do. In particular, we should not build transport
2538 * structures for the addresses.
2539 */
2540 static int sctp_process_param(struct sctp_association *asoc,
2541 union sctp_params param,
2542 const union sctp_addr *peer_addr,
2543 gfp_t gfp)
2544 {
2545 struct sctp_endpoint *ep = asoc->ep;
2546 union sctp_addr_param *addr_param;
2547 struct net *net = asoc->base.net;
2548 struct sctp_transport *t;
2549 enum sctp_scope scope;
2550 union sctp_addr addr;
2551 struct sctp_af *af;
2552 int retval = 1, i;
2553 u32 stale;
2554 __u16 sat;
2555
2556 /* We maintain all INIT parameters in network byte order all the
2557 * time. This allows us to not worry about whether the parameters
2558 * came from a fresh INIT, and INIT ACK, or were stored in a cookie.
2559 */
2560 switch (param.p->type) {
2561 case SCTP_PARAM_IPV6_ADDRESS:
2562 if (PF_INET6 != asoc->base.sk->sk_family)
2563 break;
2564 goto do_addr_param;
2565
2566 case SCTP_PARAM_IPV4_ADDRESS:
2567 /* v4 addresses are not allowed on v6-only socket */
2568 if (ipv6_only_sock(asoc->base.sk))
2569 break;
2570 do_addr_param:
2571 af = sctp_get_af_specific(param_type2af(param.p->type));
2572 if (!af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0))
2573 break;
2574 scope = sctp_scope(peer_addr);
2575 if (sctp_in_scope(net, &addr, scope))
2576 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED))
2577 return 0;
2578 break;
2579
2580 case SCTP_PARAM_COOKIE_PRESERVATIVE:
2581 if (!net->sctp.cookie_preserve_enable)
2582 break;
2583
2584 stale = ntohl(param.life->lifespan_increment);
2585
2586 /* Suggested Cookie Life span increment's unit is msec,
2587 * (1/1000sec).
2588 */
2589 asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale);
2590 break;
2591
2592 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
2593 /* Turn off the default values first so we'll know which
2594 * ones are really set by the peer.
2595 */
2596 asoc->peer.ipv4_address = 0;
2597 asoc->peer.ipv6_address = 0;
2598
2599 /* Assume that peer supports the address family
2600 * by which it sends a packet.
2601 */
2602 if (peer_addr->sa.sa_family == AF_INET6)
2603 asoc->peer.ipv6_address = 1;
2604 else if (peer_addr->sa.sa_family == AF_INET)
2605 asoc->peer.ipv4_address = 1;
2606
2607 /* Cycle through address types; avoid divide by 0. */
2608 sat = ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
2609 if (sat)
2610 sat /= sizeof(__u16);
2611
2612 for (i = 0; i < sat; ++i) {
2613 switch (param.sat->types[i]) {
2614 case SCTP_PARAM_IPV4_ADDRESS:
2615 asoc->peer.ipv4_address = 1;
2616 break;
2617
2618 case SCTP_PARAM_IPV6_ADDRESS:
2619 if (PF_INET6 == asoc->base.sk->sk_family)
2620 asoc->peer.ipv6_address = 1;
2621 break;
2622
2623 default: /* Just ignore anything else. */
2624 break;
2625 }
2626 }
2627 break;
2628
2629 case SCTP_PARAM_STATE_COOKIE:
2630 asoc->peer.cookie_len =
2631 ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
2632 kfree(asoc->peer.cookie);
2633 asoc->peer.cookie = kmemdup(param.cookie->body, asoc->peer.cookie_len, gfp);
2634 if (!asoc->peer.cookie)
2635 retval = 0;
2636 break;
2637
2638 case SCTP_PARAM_HEARTBEAT_INFO:
2639 /* Would be odd to receive, but it causes no problems. */
2640 break;
2641
2642 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
2643 /* Rejected during verify stage. */
2644 break;
2645
2646 case SCTP_PARAM_ECN_CAPABLE:
2647 if (asoc->ep->ecn_enable) {
2648 asoc->peer.ecn_capable = 1;
2649 break;
2650 }
2651 /* Fall Through */
2652 goto fall_through;
2653
2654
2655 case SCTP_PARAM_ADAPTATION_LAYER_IND:
2656 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind);
2657 break;
2658
2659 case SCTP_PARAM_SET_PRIMARY:
2660 if (!ep->asconf_enable)
2661 goto fall_through;
2662
2663 addr_param = param.v + sizeof(struct sctp_addip_param);
2664
2665 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
2666 if (!af)
2667 break;
2668
2669 if (!af->from_addr_param(&addr, addr_param,
2670 htons(asoc->peer.port), 0))
2671 break;
2672
2673 if (!af->addr_valid(&addr, NULL, NULL))
2674 break;
2675
2676 t = sctp_assoc_lookup_paddr(asoc, &addr);
2677 if (!t)
2678 break;
2679
2680 sctp_assoc_set_primary(asoc, t);
2681 break;
2682
2683 case SCTP_PARAM_SUPPORTED_EXT:
2684 sctp_process_ext_param(asoc, param);
2685 break;
2686
2687 case SCTP_PARAM_FWD_TSN_SUPPORT:
2688 if (asoc->ep->prsctp_enable) {
2689 asoc->peer.prsctp_capable = 1;
2690 break;
2691 }
2692 /* Fall Through */
2693 goto fall_through;
2694
2695 case SCTP_PARAM_RANDOM:
2696 if (!ep->auth_enable)
2697 goto fall_through;
2698
2699 /* Save peer's random parameter */
2700 kfree(asoc->peer.peer_random);
2701 asoc->peer.peer_random = kmemdup(param.p,
2702 ntohs(param.p->length), gfp);
2703 if (!asoc->peer.peer_random) {
2704 retval = 0;
2705 break;
2706 }
2707 break;
2708
2709 case SCTP_PARAM_HMAC_ALGO:
2710 if (!ep->auth_enable)
2711 goto fall_through;
2712
2713 /* Save peer's HMAC list */
2714 kfree(asoc->peer.peer_hmacs);
2715 asoc->peer.peer_hmacs = kmemdup(param.p,
2716 ntohs(param.p->length), gfp);
2717 if (!asoc->peer.peer_hmacs) {
2718 retval = 0;
2719 break;
2720 }
2721
2722 /* Set the default HMAC the peer requested*/
2723 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo);
2724 break;
2725
2726 case SCTP_PARAM_CHUNKS:
2727 if (!ep->auth_enable)
2728 goto fall_through;
2729
2730 kfree(asoc->peer.peer_chunks);
2731 asoc->peer.peer_chunks = kmemdup(param.p,
2732 ntohs(param.p->length), gfp);
2733 if (!asoc->peer.peer_chunks)
2734 retval = 0;
2735 break;
2736 fall_through:
2737 default:
2738 /* Any unrecognized parameters should have been caught
2739 * and handled by sctp_verify_param() which should be
2740 * called prior to this routine. Simply log the error
2741 * here.
2742 */
2743 pr_debug("%s: ignoring param:%d for association:%p.\n",
2744 __func__, ntohs(param.p->type), asoc);
2745 break;
2746 }
2747
2748 return retval;
2749 }
2750
2751 /* Select a new verification tag. */
2752 __u32 sctp_generate_tag(const struct sctp_endpoint *ep)
2753 {
2754 /* I believe that this random number generator complies with RFC1750.
2755 * A tag of 0 is reserved for special cases (e.g. INIT).
2756 */
2757 __u32 x;
2758
2759 do {
2760 get_random_bytes(&x, sizeof(__u32));
2761 } while (x == 0);
2762
2763 return x;
2764 }
2765
2766 /* Select an initial TSN to send during startup. */
2767 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep)
2768 {
2769 __u32 retval;
2770
2771 get_random_bytes(&retval, sizeof(__u32));
2772 return retval;
2773 }
2774
2775 /*
2776 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF)
2777 * 0 1 2 3
2778 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2779 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2780 * | Type = 0xC1 | Chunk Flags | Chunk Length |
2781 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2782 * | Serial Number |
2783 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2784 * | Address Parameter |
2785 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2786 * | ASCONF Parameter #1 |
2787 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2788 * \ \
2789 * / .... /
2790 * \ \
2791 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2792 * | ASCONF Parameter #N |
2793 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2794 *
2795 * Address Parameter and other parameter will not be wrapped in this function
2796 */
2797 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc,
2798 union sctp_addr *addr,
2799 int vparam_len)
2800 {
2801 struct sctp_addiphdr asconf;
2802 struct sctp_chunk *retval;
2803 int length = sizeof(asconf) + vparam_len;
2804 union sctp_addr_param addrparam;
2805 int addrlen;
2806 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
2807
2808 addrlen = af->to_addr_param(addr, &addrparam);
2809 if (!addrlen)
2810 return NULL;
2811 length += addrlen;
2812
2813 /* Create the chunk. */
2814 retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length,
2815 GFP_ATOMIC);
2816 if (!retval)
2817 return NULL;
2818
2819 asconf.serial = htonl(asoc->addip_serial++);
2820
2821 retval->subh.addip_hdr =
2822 sctp_addto_chunk(retval, sizeof(asconf), &asconf);
2823 retval->param_hdr.v =
2824 sctp_addto_chunk(retval, addrlen, &addrparam);
2825
2826 return retval;
2827 }
2828
2829 /* ADDIP
2830 * 3.2.1 Add IP Address
2831 * 0 1 2 3
2832 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2833 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2834 * | Type = 0xC001 | Length = Variable |
2835 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2836 * | ASCONF-Request Correlation ID |
2837 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2838 * | Address Parameter |
2839 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2840 *
2841 * 3.2.2 Delete IP Address
2842 * 0 1 2 3
2843 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2844 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2845 * | Type = 0xC002 | Length = Variable |
2846 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2847 * | ASCONF-Request Correlation ID |
2848 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2849 * | Address Parameter |
2850 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2851 *
2852 */
2853 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc,
2854 union sctp_addr *laddr,
2855 struct sockaddr *addrs,
2856 int addrcnt, __be16 flags)
2857 {
2858 union sctp_addr_param addr_param;
2859 struct sctp_addip_param param;
2860 int paramlen = sizeof(param);
2861 struct sctp_chunk *retval;
2862 int addr_param_len = 0;
2863 union sctp_addr *addr;
2864 int totallen = 0, i;
2865 int del_pickup = 0;
2866 struct sctp_af *af;
2867 void *addr_buf;
2868
2869 /* Get total length of all the address parameters. */
2870 addr_buf = addrs;
2871 for (i = 0; i < addrcnt; i++) {
2872 addr = addr_buf;
2873 af = sctp_get_af_specific(addr->v4.sin_family);
2874 addr_param_len = af->to_addr_param(addr, &addr_param);
2875
2876 totallen += paramlen;
2877 totallen += addr_param_len;
2878
2879 addr_buf += af->sockaddr_len;
2880 if (asoc->asconf_addr_del_pending && !del_pickup) {
2881 /* reuse the parameter length from the same scope one */
2882 totallen += paramlen;
2883 totallen += addr_param_len;
2884 del_pickup = 1;
2885
2886 pr_debug("%s: picked same-scope del_pending addr, "
2887 "totallen for all addresses is %d\n",
2888 __func__, totallen);
2889 }
2890 }
2891
2892 /* Create an asconf chunk with the required length. */
2893 retval = sctp_make_asconf(asoc, laddr, totallen);
2894 if (!retval)
2895 return NULL;
2896
2897 /* Add the address parameters to the asconf chunk. */
2898 addr_buf = addrs;
2899 for (i = 0; i < addrcnt; i++) {
2900 addr = addr_buf;
2901 af = sctp_get_af_specific(addr->v4.sin_family);
2902 addr_param_len = af->to_addr_param(addr, &addr_param);
2903 param.param_hdr.type = flags;
2904 param.param_hdr.length = htons(paramlen + addr_param_len);
2905 param.crr_id = htonl(i);
2906
2907 sctp_addto_chunk(retval, paramlen, ¶m);
2908 sctp_addto_chunk(retval, addr_param_len, &addr_param);
2909
2910 addr_buf += af->sockaddr_len;
2911 }
2912 if (flags == SCTP_PARAM_ADD_IP && del_pickup) {
2913 addr = asoc->asconf_addr_del_pending;
2914 af = sctp_get_af_specific(addr->v4.sin_family);
2915 addr_param_len = af->to_addr_param(addr, &addr_param);
2916 param.param_hdr.type = SCTP_PARAM_DEL_IP;
2917 param.param_hdr.length = htons(paramlen + addr_param_len);
2918 param.crr_id = htonl(i);
2919
2920 sctp_addto_chunk(retval, paramlen, ¶m);
2921 sctp_addto_chunk(retval, addr_param_len, &addr_param);
2922 }
2923 return retval;
2924 }
2925
2926 /* ADDIP
2927 * 3.2.4 Set Primary IP Address
2928 * 0 1 2 3
2929 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2930 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2931 * | Type =0xC004 | Length = Variable |
2932 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2933 * | ASCONF-Request Correlation ID |
2934 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2935 * | Address Parameter |
2936 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2937 *
2938 * Create an ASCONF chunk with Set Primary IP address parameter.
2939 */
2940 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
2941 union sctp_addr *addr)
2942 {
2943 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
2944 union sctp_addr_param addrparam;
2945 struct sctp_addip_param param;
2946 struct sctp_chunk *retval;
2947 int len = sizeof(param);
2948 int addrlen;
2949
2950 addrlen = af->to_addr_param(addr, &addrparam);
2951 if (!addrlen)
2952 return NULL;
2953 len += addrlen;
2954
2955 /* Create the chunk and make asconf header. */
2956 retval = sctp_make_asconf(asoc, addr, len);
2957 if (!retval)
2958 return NULL;
2959
2960 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY;
2961 param.param_hdr.length = htons(len);
2962 param.crr_id = 0;
2963
2964 sctp_addto_chunk(retval, sizeof(param), ¶m);
2965 sctp_addto_chunk(retval, addrlen, &addrparam);
2966
2967 return retval;
2968 }
2969
2970 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK)
2971 * 0 1 2 3
2972 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2973 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2974 * | Type = 0x80 | Chunk Flags | Chunk Length |
2975 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2976 * | Serial Number |
2977 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2978 * | ASCONF Parameter Response#1 |
2979 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2980 * \ \
2981 * / .... /
2982 * \ \
2983 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2984 * | ASCONF Parameter Response#N |
2985 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2986 *
2987 * Create an ASCONF_ACK chunk with enough space for the parameter responses.
2988 */
2989 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc,
2990 __u32 serial, int vparam_len)
2991 {
2992 struct sctp_addiphdr asconf;
2993 struct sctp_chunk *retval;
2994 int length = sizeof(asconf) + vparam_len;
2995
2996 /* Create the chunk. */
2997 retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length,
2998 GFP_ATOMIC);
2999 if (!retval)
3000 return NULL;
3001
3002 asconf.serial = htonl(serial);
3003
3004 retval->subh.addip_hdr =
3005 sctp_addto_chunk(retval, sizeof(asconf), &asconf);
3006
3007 return retval;
3008 }
3009
3010 /* Add response parameters to an ASCONF_ACK chunk. */
3011 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id,
3012 __be16 err_code,
3013 struct sctp_addip_param *asconf_param)
3014 {
3015 struct sctp_addip_param ack_param;
3016 struct sctp_errhdr err_param;
3017 int asconf_param_len = 0;
3018 int err_param_len = 0;
3019 __be16 response_type;
3020
3021 if (SCTP_ERROR_NO_ERROR == err_code) {
3022 response_type = SCTP_PARAM_SUCCESS_REPORT;
3023 } else {
3024 response_type = SCTP_PARAM_ERR_CAUSE;
3025 err_param_len = sizeof(err_param);
3026 if (asconf_param)
3027 asconf_param_len =
3028 ntohs(asconf_param->param_hdr.length);
3029 }
3030
3031 /* Add Success Indication or Error Cause Indication parameter. */
3032 ack_param.param_hdr.type = response_type;
3033 ack_param.param_hdr.length = htons(sizeof(ack_param) +
3034 err_param_len +
3035 asconf_param_len);
3036 ack_param.crr_id = crr_id;
3037 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param);
3038
3039 if (SCTP_ERROR_NO_ERROR == err_code)
3040 return;
3041
3042 /* Add Error Cause parameter. */
3043 err_param.cause = err_code;
3044 err_param.length = htons(err_param_len + asconf_param_len);
3045 sctp_addto_chunk(chunk, err_param_len, &err_param);
3046
3047 /* Add the failed TLV copied from ASCONF chunk. */
3048 if (asconf_param)
3049 sctp_addto_chunk(chunk, asconf_param_len, asconf_param);
3050 }
3051
3052 /* Process a asconf parameter. */
3053 static __be16 sctp_process_asconf_param(struct sctp_association *asoc,
3054 struct sctp_chunk *asconf,
3055 struct sctp_addip_param *asconf_param)
3056 {
3057 union sctp_addr_param *addr_param;
3058 struct sctp_transport *peer;
3059 union sctp_addr addr;
3060 struct sctp_af *af;
3061
3062 addr_param = (void *)asconf_param + sizeof(*asconf_param);
3063
3064 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP &&
3065 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP &&
3066 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY)
3067 return SCTP_ERROR_UNKNOWN_PARAM;
3068
3069 switch (addr_param->p.type) {
3070 case SCTP_PARAM_IPV6_ADDRESS:
3071 if (!asoc->peer.ipv6_address)
3072 return SCTP_ERROR_DNS_FAILED;
3073 break;
3074 case SCTP_PARAM_IPV4_ADDRESS:
3075 if (!asoc->peer.ipv4_address)
3076 return SCTP_ERROR_DNS_FAILED;
3077 break;
3078 default:
3079 return SCTP_ERROR_DNS_FAILED;
3080 }
3081
3082 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
3083 if (unlikely(!af))
3084 return SCTP_ERROR_DNS_FAILED;
3085
3086 if (!af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0))
3087 return SCTP_ERROR_DNS_FAILED;
3088
3089 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast
3090 * or multicast address.
3091 * (note: wildcard is permitted and requires special handling so
3092 * make sure we check for that)
3093 */
3094 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb))
3095 return SCTP_ERROR_DNS_FAILED;
3096
3097 switch (asconf_param->param_hdr.type) {
3098 case SCTP_PARAM_ADD_IP:
3099 /* Section 4.2.1:
3100 * If the address 0.0.0.0 or ::0 is provided, the source
3101 * address of the packet MUST be added.
3102 */
3103 if (af->is_any(&addr))
3104 memcpy(&addr, &asconf->source, sizeof(addr));
3105
3106 if (security_sctp_bind_connect(asoc->ep->base.sk,
3107 SCTP_PARAM_ADD_IP,
3108 (struct sockaddr *)&addr,
3109 af->sockaddr_len))
3110 return SCTP_ERROR_REQ_REFUSED;
3111
3112 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address
3113 * request and does not have the local resources to add this
3114 * new address to the association, it MUST return an Error
3115 * Cause TLV set to the new error code 'Operation Refused
3116 * Due to Resource Shortage'.
3117 */
3118
3119 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED);
3120 if (!peer)
3121 return SCTP_ERROR_RSRC_LOW;
3122
3123 /* Start the heartbeat timer. */
3124 sctp_transport_reset_hb_timer(peer);
3125 asoc->new_transport = peer;
3126 break;
3127 case SCTP_PARAM_DEL_IP:
3128 /* ADDIP 4.3 D7) If a request is received to delete the
3129 * last remaining IP address of a peer endpoint, the receiver
3130 * MUST send an Error Cause TLV with the error cause set to the
3131 * new error code 'Request to Delete Last Remaining IP Address'.
3132 */
3133 if (asoc->peer.transport_count == 1)
3134 return SCTP_ERROR_DEL_LAST_IP;
3135
3136 /* ADDIP 4.3 D8) If a request is received to delete an IP
3137 * address which is also the source address of the IP packet
3138 * which contained the ASCONF chunk, the receiver MUST reject
3139 * this request. To reject the request the receiver MUST send
3140 * an Error Cause TLV set to the new error code 'Request to
3141 * Delete Source IP Address'
3142 */
3143 if (sctp_cmp_addr_exact(&asconf->source, &addr))
3144 return SCTP_ERROR_DEL_SRC_IP;
3145
3146 /* Section 4.2.2
3147 * If the address 0.0.0.0 or ::0 is provided, all
3148 * addresses of the peer except the source address of the
3149 * packet MUST be deleted.
3150 */
3151 if (af->is_any(&addr)) {
3152 sctp_assoc_set_primary(asoc, asconf->transport);
3153 sctp_assoc_del_nonprimary_peers(asoc,
3154 asconf->transport);
3155 return SCTP_ERROR_NO_ERROR;
3156 }
3157
3158 /* If the address is not part of the association, the
3159 * ASCONF-ACK with Error Cause Indication Parameter
3160 * which including cause of Unresolvable Address should
3161 * be sent.
3162 */
3163 peer = sctp_assoc_lookup_paddr(asoc, &addr);
3164 if (!peer)
3165 return SCTP_ERROR_DNS_FAILED;
3166
3167 sctp_assoc_rm_peer(asoc, peer);
3168 break;
3169 case SCTP_PARAM_SET_PRIMARY:
3170 /* ADDIP Section 4.2.4
3171 * If the address 0.0.0.0 or ::0 is provided, the receiver
3172 * MAY mark the source address of the packet as its
3173 * primary.
3174 */
3175 if (af->is_any(&addr))
3176 memcpy(&addr, sctp_source(asconf), sizeof(addr));
3177
3178 if (security_sctp_bind_connect(asoc->ep->base.sk,
3179 SCTP_PARAM_SET_PRIMARY,
3180 (struct sockaddr *)&addr,
3181 af->sockaddr_len))
3182 return SCTP_ERROR_REQ_REFUSED;
3183
3184 peer = sctp_assoc_lookup_paddr(asoc, &addr);
3185 if (!peer)
3186 return SCTP_ERROR_DNS_FAILED;
3187
3188 sctp_assoc_set_primary(asoc, peer);
3189 break;
3190 }
3191
3192 return SCTP_ERROR_NO_ERROR;
3193 }
3194
3195 /* Verify the ASCONF packet before we process it. */
3196 bool sctp_verify_asconf(const struct sctp_association *asoc,
3197 struct sctp_chunk *chunk, bool addr_param_needed,
3198 struct sctp_paramhdr **errp)
3199 {
3200 struct sctp_addip_chunk *addip;
3201 bool addr_param_seen = false;
3202 union sctp_params param;
3203
3204 addip = (struct sctp_addip_chunk *)chunk->chunk_hdr;
3205 sctp_walk_params(param, addip) {
3206 size_t length = ntohs(param.p->length);
3207
3208 *errp = param.p;
3209 switch (param.p->type) {
3210 case SCTP_PARAM_ERR_CAUSE:
3211 break;
3212 case SCTP_PARAM_IPV4_ADDRESS:
3213 if (length != sizeof(struct sctp_ipv4addr_param))
3214 return false;
3215 /* ensure there is only one addr param and it's in the
3216 * beginning of addip_hdr params, or we reject it.
3217 */
3218 if (param.v != (addip + 1))
3219 return false;
3220 addr_param_seen = true;
3221 break;
3222 case SCTP_PARAM_IPV6_ADDRESS:
3223 if (length != sizeof(struct sctp_ipv6addr_param))
3224 return false;
3225 if (param.v != (addip + 1))
3226 return false;
3227 addr_param_seen = true;
3228 break;
3229 case SCTP_PARAM_ADD_IP:
3230 case SCTP_PARAM_DEL_IP:
3231 case SCTP_PARAM_SET_PRIMARY:
3232 /* In ASCONF chunks, these need to be first. */
3233 if (addr_param_needed && !addr_param_seen)
3234 return false;
3235 length = ntohs(param.addip->param_hdr.length);
3236 if (length < sizeof(struct sctp_addip_param) +
3237 sizeof(**errp))
3238 return false;
3239 break;
3240 case SCTP_PARAM_SUCCESS_REPORT:
3241 case SCTP_PARAM_ADAPTATION_LAYER_IND:
3242 if (length != sizeof(struct sctp_addip_param))
3243 return false;
3244 break;
3245 default:
3246 /* This is unknown to us, reject! */
3247 return false;
3248 }
3249 }
3250
3251 /* Remaining sanity checks. */
3252 if (addr_param_needed && !addr_param_seen)
3253 return false;
3254 if (!addr_param_needed && addr_param_seen)
3255 return false;
3256 if (param.v != chunk->chunk_end)
3257 return false;
3258
3259 return true;
3260 }
3261
3262 /* Process an incoming ASCONF chunk with the next expected serial no. and
3263 * return an ASCONF_ACK chunk to be sent in response.
3264 */
3265 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
3266 struct sctp_chunk *asconf)
3267 {
3268 union sctp_addr_param *addr_param;
3269 struct sctp_addip_chunk *addip;
3270 struct sctp_chunk *asconf_ack;
3271 bool all_param_pass = true;
3272 struct sctp_addiphdr *hdr;
3273 int length = 0, chunk_len;
3274 union sctp_params param;
3275 __be16 err_code;
3276 __u32 serial;
3277
3278 addip = (struct sctp_addip_chunk *)asconf->chunk_hdr;
3279 chunk_len = ntohs(asconf->chunk_hdr->length) -
3280 sizeof(struct sctp_chunkhdr);
3281 hdr = (struct sctp_addiphdr *)asconf->skb->data;
3282 serial = ntohl(hdr->serial);
3283
3284 /* Skip the addiphdr and store a pointer to address parameter. */
3285 length = sizeof(*hdr);
3286 addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
3287 chunk_len -= length;
3288
3289 /* Skip the address parameter and store a pointer to the first
3290 * asconf parameter.
3291 */
3292 length = ntohs(addr_param->p.length);
3293 chunk_len -= length;
3294
3295 /* create an ASCONF_ACK chunk.
3296 * Based on the definitions of parameters, we know that the size of
3297 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF
3298 * parameters.
3299 */
3300 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4);
3301 if (!asconf_ack)
3302 goto done;
3303
3304 /* Process the TLVs contained within the ASCONF chunk. */
3305 sctp_walk_params(param, addip) {
3306 /* Skip preceding address parameters. */
3307 if (param.p->type == SCTP_PARAM_IPV4_ADDRESS ||
3308 param.p->type == SCTP_PARAM_IPV6_ADDRESS)
3309 continue;
3310
3311 err_code = sctp_process_asconf_param(asoc, asconf,
3312 param.addip);
3313 /* ADDIP 4.1 A7)
3314 * If an error response is received for a TLV parameter,
3315 * all TLVs with no response before the failed TLV are
3316 * considered successful if not reported. All TLVs after
3317 * the failed response are considered unsuccessful unless
3318 * a specific success indication is present for the parameter.
3319 */
3320 if (err_code != SCTP_ERROR_NO_ERROR)
3321 all_param_pass = false;
3322 if (!all_param_pass)
3323 sctp_add_asconf_response(asconf_ack, param.addip->crr_id,
3324 err_code, param.addip);
3325
3326 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add
3327 * an IP address sends an 'Out of Resource' in its response, it
3328 * MUST also fail any subsequent add or delete requests bundled
3329 * in the ASCONF.
3330 */
3331 if (err_code == SCTP_ERROR_RSRC_LOW)
3332 goto done;
3333 }
3334 done:
3335 asoc->peer.addip_serial++;
3336
3337 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc
3338 * after freeing the reference to old asconf ack if any.
3339 */
3340 if (asconf_ack) {
3341 sctp_chunk_hold(asconf_ack);
3342 list_add_tail(&asconf_ack->transmitted_list,
3343 &asoc->asconf_ack_list);
3344 }
3345
3346 return asconf_ack;
3347 }
3348
3349 /* Process a asconf parameter that is successfully acked. */
3350 static void sctp_asconf_param_success(struct sctp_association *asoc,
3351 struct sctp_addip_param *asconf_param)
3352 {
3353 struct sctp_bind_addr *bp = &asoc->base.bind_addr;
3354 union sctp_addr_param *addr_param;
3355 struct sctp_sockaddr_entry *saddr;
3356 struct sctp_transport *transport;
3357 union sctp_addr addr;
3358 struct sctp_af *af;
3359
3360 addr_param = (void *)asconf_param + sizeof(*asconf_param);
3361
3362 /* We have checked the packet before, so we do not check again. */
3363 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
3364 if (!af->from_addr_param(&addr, addr_param, htons(bp->port), 0))
3365 return;
3366
3367 switch (asconf_param->param_hdr.type) {
3368 case SCTP_PARAM_ADD_IP:
3369 /* This is always done in BH context with a socket lock
3370 * held, so the list can not change.
3371 */
3372 local_bh_disable();
3373 list_for_each_entry(saddr, &bp->address_list, list) {
3374 if (sctp_cmp_addr_exact(&saddr->a, &addr))
3375 saddr->state = SCTP_ADDR_SRC;
3376 }
3377 local_bh_enable();
3378 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
3379 transports) {
3380 sctp_transport_dst_release(transport);
3381 }
3382 break;
3383 case SCTP_PARAM_DEL_IP:
3384 local_bh_disable();
3385 sctp_del_bind_addr(bp, &addr);
3386 if (asoc->asconf_addr_del_pending != NULL &&
3387 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) {
3388 kfree(asoc->asconf_addr_del_pending);
3389 asoc->asconf_addr_del_pending = NULL;
3390 }
3391 local_bh_enable();
3392 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
3393 transports) {
3394 sctp_transport_dst_release(transport);
3395 }
3396 break;
3397 default:
3398 break;
3399 }
3400 }
3401
3402 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk
3403 * for the given asconf parameter. If there is no response for this parameter,
3404 * return the error code based on the third argument 'no_err'.
3405 * ADDIP 4.1
3406 * A7) If an error response is received for a TLV parameter, all TLVs with no
3407 * response before the failed TLV are considered successful if not reported.
3408 * All TLVs after the failed response are considered unsuccessful unless a
3409 * specific success indication is present for the parameter.
3410 */
3411 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack,
3412 struct sctp_addip_param *asconf_param,
3413 int no_err)
3414 {
3415 struct sctp_addip_param *asconf_ack_param;
3416 struct sctp_errhdr *err_param;
3417 int asconf_ack_len;
3418 __be16 err_code;
3419 int length;
3420
3421 if (no_err)
3422 err_code = SCTP_ERROR_NO_ERROR;
3423 else
3424 err_code = SCTP_ERROR_REQ_REFUSED;
3425
3426 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) -
3427 sizeof(struct sctp_chunkhdr);
3428
3429 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to
3430 * the first asconf_ack parameter.
3431 */
3432 length = sizeof(struct sctp_addiphdr);
3433 asconf_ack_param = (struct sctp_addip_param *)(asconf_ack->skb->data +
3434 length);
3435 asconf_ack_len -= length;
3436
3437 while (asconf_ack_len > 0) {
3438 if (asconf_ack_param->crr_id == asconf_param->crr_id) {
3439 switch (asconf_ack_param->param_hdr.type) {
3440 case SCTP_PARAM_SUCCESS_REPORT:
3441 return SCTP_ERROR_NO_ERROR;
3442 case SCTP_PARAM_ERR_CAUSE:
3443 length = sizeof(*asconf_ack_param);
3444 err_param = (void *)asconf_ack_param + length;
3445 asconf_ack_len -= length;
3446 if (asconf_ack_len > 0)
3447 return err_param->cause;
3448 else
3449 return SCTP_ERROR_INV_PARAM;
3450 break;
3451 default:
3452 return SCTP_ERROR_INV_PARAM;
3453 }
3454 }
3455
3456 length = ntohs(asconf_ack_param->param_hdr.length);
3457 asconf_ack_param = (void *)asconf_ack_param + length;
3458 asconf_ack_len -= length;
3459 }
3460
3461 return err_code;
3462 }
3463
3464 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */
3465 int sctp_process_asconf_ack(struct sctp_association *asoc,
3466 struct sctp_chunk *asconf_ack)
3467 {
3468 struct sctp_chunk *asconf = asoc->addip_last_asconf;
3469 struct sctp_addip_param *asconf_param;
3470 __be16 err_code = SCTP_ERROR_NO_ERROR;
3471 union sctp_addr_param *addr_param;
3472 int asconf_len = asconf->skb->len;
3473 int all_param_pass = 0;
3474 int length = 0;
3475 int no_err = 1;
3476 int retval = 0;
3477
3478 /* Skip the chunkhdr and addiphdr from the last asconf sent and store
3479 * a pointer to address parameter.
3480 */
3481 length = sizeof(struct sctp_addip_chunk);
3482 addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
3483 asconf_len -= length;
3484
3485 /* Skip the address parameter in the last asconf sent and store a
3486 * pointer to the first asconf parameter.
3487 */
3488 length = ntohs(addr_param->p.length);
3489 asconf_param = (void *)addr_param + length;
3490 asconf_len -= length;
3491
3492 /* ADDIP 4.1
3493 * A8) If there is no response(s) to specific TLV parameter(s), and no
3494 * failures are indicated, then all request(s) are considered
3495 * successful.
3496 */
3497 if (asconf_ack->skb->len == sizeof(struct sctp_addiphdr))
3498 all_param_pass = 1;
3499
3500 /* Process the TLVs contained in the last sent ASCONF chunk. */
3501 while (asconf_len > 0) {
3502 if (all_param_pass)
3503 err_code = SCTP_ERROR_NO_ERROR;
3504 else {
3505 err_code = sctp_get_asconf_response(asconf_ack,
3506 asconf_param,
3507 no_err);
3508 if (no_err && (SCTP_ERROR_NO_ERROR != err_code))
3509 no_err = 0;
3510 }
3511
3512 switch (err_code) {
3513 case SCTP_ERROR_NO_ERROR:
3514 sctp_asconf_param_success(asoc, asconf_param);
3515 break;
3516
3517 case SCTP_ERROR_RSRC_LOW:
3518 retval = 1;
3519 break;
3520
3521 case SCTP_ERROR_UNKNOWN_PARAM:
3522 /* Disable sending this type of asconf parameter in
3523 * future.
3524 */
3525 asoc->peer.addip_disabled_mask |=
3526 asconf_param->param_hdr.type;
3527 break;
3528
3529 case SCTP_ERROR_REQ_REFUSED:
3530 case SCTP_ERROR_DEL_LAST_IP:
3531 case SCTP_ERROR_DEL_SRC_IP:
3532 default:
3533 break;
3534 }
3535
3536 /* Skip the processed asconf parameter and move to the next
3537 * one.
3538 */
3539 length = ntohs(asconf_param->param_hdr.length);
3540 asconf_param = (void *)asconf_param + length;
3541 asconf_len -= length;
3542 }
3543
3544 if (no_err && asoc->src_out_of_asoc_ok) {
3545 asoc->src_out_of_asoc_ok = 0;
3546 sctp_transport_immediate_rtx(asoc->peer.primary_path);
3547 }
3548
3549 /* Free the cached last sent asconf chunk. */
3550 list_del_init(&asconf->transmitted_list);
3551 sctp_chunk_free(asconf);
3552 asoc->addip_last_asconf = NULL;
3553
3554 return retval;
3555 }
3556
3557 /* Make a FWD TSN chunk. */
3558 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
3559 __u32 new_cum_tsn, size_t nstreams,
3560 struct sctp_fwdtsn_skip *skiplist)
3561 {
3562 struct sctp_chunk *retval = NULL;
3563 struct sctp_fwdtsn_hdr ftsn_hdr;
3564 struct sctp_fwdtsn_skip skip;
3565 size_t hint;
3566 int i;
3567
3568 hint = (nstreams + 1) * sizeof(__u32);
3569
3570 retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint, GFP_ATOMIC);
3571
3572 if (!retval)
3573 return NULL;
3574
3575 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn);
3576 retval->subh.fwdtsn_hdr =
3577 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr);
3578
3579 for (i = 0; i < nstreams; i++) {
3580 skip.stream = skiplist[i].stream;
3581 skip.ssn = skiplist[i].ssn;
3582 sctp_addto_chunk(retval, sizeof(skip), &skip);
3583 }
3584
3585 return retval;
3586 }
3587
3588 struct sctp_chunk *sctp_make_ifwdtsn(const struct sctp_association *asoc,
3589 __u32 new_cum_tsn, size_t nstreams,
3590 struct sctp_ifwdtsn_skip *skiplist)
3591 {
3592 struct sctp_chunk *retval = NULL;
3593 struct sctp_ifwdtsn_hdr ftsn_hdr;
3594 size_t hint;
3595
3596 hint = (nstreams + 1) * sizeof(__u32);
3597
3598 retval = sctp_make_control(asoc, SCTP_CID_I_FWD_TSN, 0, hint,
3599 GFP_ATOMIC);
3600 if (!retval)
3601 return NULL;
3602
3603 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn);
3604 retval->subh.ifwdtsn_hdr =
3605 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr);
3606
3607 sctp_addto_chunk(retval, nstreams * sizeof(skiplist[0]), skiplist);
3608
3609 return retval;
3610 }
3611
3612 /* RE-CONFIG 3.1 (RE-CONFIG chunk)
3613 * 0 1 2 3
3614 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
3615 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3616 * | Type = 130 | Chunk Flags | Chunk Length |
3617 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3618 * \ \
3619 * / Re-configuration Parameter /
3620 * \ \
3621 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3622 * \ \
3623 * / Re-configuration Parameter (optional) /
3624 * \ \
3625 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3626 */
3627 static struct sctp_chunk *sctp_make_reconf(const struct sctp_association *asoc,
3628 int length)
3629 {
3630 struct sctp_reconf_chunk *reconf;
3631 struct sctp_chunk *retval;
3632
3633 retval = sctp_make_control(asoc, SCTP_CID_RECONF, 0, length,
3634 GFP_ATOMIC);
3635 if (!retval)
3636 return NULL;
3637
3638 reconf = (struct sctp_reconf_chunk *)retval->chunk_hdr;
3639 retval->param_hdr.v = (u8 *)(reconf + 1);
3640
3641 return retval;
3642 }
3643
3644 /* RE-CONFIG 4.1 (STREAM OUT RESET)
3645 * 0 1 2 3
3646 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
3647 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3648 * | Parameter Type = 13 | Parameter Length = 16 + 2 * N |
3649 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3650 * | Re-configuration Request Sequence Number |
3651 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3652 * | Re-configuration Response Sequence Number |
3653 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3654 * | Sender's Last Assigned TSN |
3655 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3656 * | Stream Number 1 (optional) | Stream Number 2 (optional) |
3657 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3658 * / ...... /
3659 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3660 * | Stream Number N-1 (optional) | Stream Number N (optional) |
3661 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3662 *
3663 * RE-CONFIG 4.2 (STREAM IN RESET)
3664 * 0 1 2 3
3665 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
3666 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3667 * | Parameter Type = 14 | Parameter Length = 8 + 2 * N |
3668 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3669 * | Re-configuration Request Sequence Number |
3670 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3671 * | Stream Number 1 (optional) | Stream Number 2 (optional) |
3672 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3673 * / ...... /
3674 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3675 * | Stream Number N-1 (optional) | Stream Number N (optional) |
3676 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3677 */
3678 struct sctp_chunk *sctp_make_strreset_req(
3679 const struct sctp_association *asoc,
3680 __u16 stream_num, __be16 *stream_list,
3681 bool out, bool in)
3682 {
3683 __u16 stream_len = stream_num * sizeof(__u16);
3684 struct sctp_strreset_outreq outreq;
3685 struct sctp_strreset_inreq inreq;
3686 struct sctp_chunk *retval;
3687 __u16 outlen, inlen;
3688
3689 outlen = (sizeof(outreq) + stream_len) * out;
3690 inlen = (sizeof(inreq) + stream_len) * in;
3691
3692 retval = sctp_make_reconf(asoc, SCTP_PAD4(outlen) + SCTP_PAD4(inlen));
3693 if (!retval)
3694 return NULL;
3695
3696 if (outlen) {
3697 outreq.param_hdr.type = SCTP_PARAM_RESET_OUT_REQUEST;
3698 outreq.param_hdr.length = htons(outlen);
3699 outreq.request_seq = htonl(asoc->strreset_outseq);
3700 outreq.response_seq = htonl(asoc->strreset_inseq - 1);
3701 outreq.send_reset_at_tsn = htonl(asoc->next_tsn - 1);
3702
3703 sctp_addto_chunk(retval, sizeof(outreq), &outreq);
3704
3705 if (stream_len)
3706 sctp_addto_chunk(retval, stream_len, stream_list);
3707 }
3708
3709 if (inlen) {
3710 inreq.param_hdr.type = SCTP_PARAM_RESET_IN_REQUEST;
3711 inreq.param_hdr.length = htons(inlen);
3712 inreq.request_seq = htonl(asoc->strreset_outseq + out);
3713
3714 sctp_addto_chunk(retval, sizeof(inreq), &inreq);
3715
3716 if (stream_len)
3717 sctp_addto_chunk(retval, stream_len, stream_list);
3718 }
3719
3720 return retval;
3721 }
3722
3723 /* RE-CONFIG 4.3 (SSN/TSN RESET ALL)
3724 * 0 1 2 3
3725 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
3726 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3727 * | Parameter Type = 15 | Parameter Length = 8 |
3728 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3729 * | Re-configuration Request Sequence Number |
3730 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3731 */
3732 struct sctp_chunk *sctp_make_strreset_tsnreq(
3733 const struct sctp_association *asoc)
3734 {
3735 struct sctp_strreset_tsnreq tsnreq;
3736 __u16 length = sizeof(tsnreq);
3737 struct sctp_chunk *retval;
3738
3739 retval = sctp_make_reconf(asoc, length);
3740 if (!retval)
3741 return NULL;
3742
3743 tsnreq.param_hdr.type = SCTP_PARAM_RESET_TSN_REQUEST;
3744 tsnreq.param_hdr.length = htons(length);
3745 tsnreq.request_seq = htonl(asoc->strreset_outseq);
3746
3747 sctp_addto_chunk(retval, sizeof(tsnreq), &tsnreq);
3748
3749 return retval;
3750 }
3751
3752 /* RE-CONFIG 4.5/4.6 (ADD STREAM)
3753 * 0 1 2 3
3754 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
3755 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3756 * | Parameter Type = 17 | Parameter Length = 12 |
3757 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3758 * | Re-configuration Request Sequence Number |
3759 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3760 * | Number of new streams | Reserved |
3761 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3762 */
3763 struct sctp_chunk *sctp_make_strreset_addstrm(
3764 const struct sctp_association *asoc,
3765 __u16 out, __u16 in)
3766 {
3767 struct sctp_strreset_addstrm addstrm;
3768 __u16 size = sizeof(addstrm);
3769 struct sctp_chunk *retval;
3770
3771 retval = sctp_make_reconf(asoc, (!!out + !!in) * size);
3772 if (!retval)
3773 return NULL;
3774
3775 if (out) {
3776 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_OUT_STREAMS;
3777 addstrm.param_hdr.length = htons(size);
3778 addstrm.number_of_streams = htons(out);
3779 addstrm.request_seq = htonl(asoc->strreset_outseq);
3780 addstrm.reserved = 0;
3781
3782 sctp_addto_chunk(retval, size, &addstrm);
3783 }
3784
3785 if (in) {
3786 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_IN_STREAMS;
3787 addstrm.param_hdr.length = htons(size);
3788 addstrm.number_of_streams = htons(in);
3789 addstrm.request_seq = htonl(asoc->strreset_outseq + !!out);
3790 addstrm.reserved = 0;
3791
3792 sctp_addto_chunk(retval, size, &addstrm);
3793 }
3794
3795 return retval;
3796 }
3797
3798 /* RE-CONFIG 4.4 (RESP)
3799 * 0 1 2 3
3800 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
3801 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3802 * | Parameter Type = 16 | Parameter Length |
3803 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3804 * | Re-configuration Response Sequence Number |
3805 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3806 * | Result |
3807 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3808 */
3809 struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc,
3810 __u32 result, __u32 sn)
3811 {
3812 struct sctp_strreset_resp resp;
3813 __u16 length = sizeof(resp);
3814 struct sctp_chunk *retval;
3815
3816 retval = sctp_make_reconf(asoc, length);
3817 if (!retval)
3818 return NULL;
3819
3820 resp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE;
3821 resp.param_hdr.length = htons(length);
3822 resp.response_seq = htonl(sn);
3823 resp.result = htonl(result);
3824
3825 sctp_addto_chunk(retval, sizeof(resp), &resp);
3826
3827 return retval;
3828 }
3829
3830 /* RE-CONFIG 4.4 OPTIONAL (TSNRESP)
3831 * 0 1 2 3
3832 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
3833 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3834 * | Parameter Type = 16 | Parameter Length |
3835 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3836 * | Re-configuration Response Sequence Number |
3837 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3838 * | Result |
3839 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3840 * | Sender's Next TSN (optional) |
3841 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3842 * | Receiver's Next TSN (optional) |
3843 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3844 */
3845 struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc,
3846 __u32 result, __u32 sn,
3847 __u32 sender_tsn,
3848 __u32 receiver_tsn)
3849 {
3850 struct sctp_strreset_resptsn tsnresp;
3851 __u16 length = sizeof(tsnresp);
3852 struct sctp_chunk *retval;
3853
3854 retval = sctp_make_reconf(asoc, length);
3855 if (!retval)
3856 return NULL;
3857
3858 tsnresp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE;
3859 tsnresp.param_hdr.length = htons(length);
3860
3861 tsnresp.response_seq = htonl(sn);
3862 tsnresp.result = htonl(result);
3863 tsnresp.senders_next_tsn = htonl(sender_tsn);
3864 tsnresp.receivers_next_tsn = htonl(receiver_tsn);
3865
3866 sctp_addto_chunk(retval, sizeof(tsnresp), &tsnresp);
3867
3868 return retval;
3869 }
3870
3871 bool sctp_verify_reconf(const struct sctp_association *asoc,
3872 struct sctp_chunk *chunk,
3873 struct sctp_paramhdr **errp)
3874 {
3875 struct sctp_reconf_chunk *hdr;
3876 union sctp_params param;
3877 __be16 last = 0;
3878 __u16 cnt = 0;
3879
3880 hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr;
3881 sctp_walk_params(param, hdr) {
3882 __u16 length = ntohs(param.p->length);
3883
3884 *errp = param.p;
3885 if (cnt++ > 2)
3886 return false;
3887 switch (param.p->type) {
3888 case SCTP_PARAM_RESET_OUT_REQUEST:
3889 if (length < sizeof(struct sctp_strreset_outreq) ||
3890 (last && last != SCTP_PARAM_RESET_RESPONSE &&
3891 last != SCTP_PARAM_RESET_IN_REQUEST))
3892 return false;
3893 break;
3894 case SCTP_PARAM_RESET_IN_REQUEST:
3895 if (length < sizeof(struct sctp_strreset_inreq) ||
3896 (last && last != SCTP_PARAM_RESET_OUT_REQUEST))
3897 return false;
3898 break;
3899 case SCTP_PARAM_RESET_RESPONSE:
3900 if ((length != sizeof(struct sctp_strreset_resp) &&
3901 length != sizeof(struct sctp_strreset_resptsn)) ||
3902 (last && last != SCTP_PARAM_RESET_RESPONSE &&
3903 last != SCTP_PARAM_RESET_OUT_REQUEST))
3904 return false;
3905 break;
3906 case SCTP_PARAM_RESET_TSN_REQUEST:
3907 if (length !=
3908 sizeof(struct sctp_strreset_tsnreq) || last)
3909 return false;
3910 break;
3911 case SCTP_PARAM_RESET_ADD_IN_STREAMS:
3912 if (length != sizeof(struct sctp_strreset_addstrm) ||
3913 (last && last != SCTP_PARAM_RESET_ADD_OUT_STREAMS))
3914 return false;
3915 break;
3916 case SCTP_PARAM_RESET_ADD_OUT_STREAMS:
3917 if (length != sizeof(struct sctp_strreset_addstrm) ||
3918 (last && last != SCTP_PARAM_RESET_ADD_IN_STREAMS))
3919 return false;
3920 break;
3921 default:
3922 return false;
3923 }
3924
3925 last = param.p->type;
3926 }
3927
3928 return true;
3929 }
3930
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